JavaScript - This Page Returnes An Arror Message

<script type="JavaScript">


function showMessage()
{
    var d = new Date();
    var day = d.getDay();     // Note: Sunday=0, Monday=1, etc...

    switch( true )
   
        }
        case ( day == 6 ) :
        {
          document.write("Today is saturday!")
        }
         case ( day == 5 ) :
        {
          document.write("Today is friday!")
        }
         case ( day == 4 ) :
        {
          document.write("Today is thursday!")
        }
         case ( day == 3 ) :
        {
          document.write("Today is wednesday!")
        }
         case ( day == 2 ) :
        {
          document.write("Today is tuesday!")
        }
         case ( day == 1 ) :
        {
          document.write("Today is monday!")
        }
         case ( day == 0 ) :
        {
          document.write("Today is sunday!")
        }
    }    
}

    </script>

<form action="mailto:hummdedum@felloff.com" method="post" name="form" onSubmit="return isFormValid();">

* First Name: <input type="text"  name="FName" id="FName" onblur="checkFName();"/><label id="labelFName"></label><br />
* Last Name: <input type="text" name="LName" id="LName"onblur="checkLName();"/><label id="labelLName"></label><br />



* Password: <input type="password" id="pw" name="Password" onblur="checkpw();" id="pw"/><label id="labelpw"></label><br />
*Re-type Password: <input type="password" name="2Password" id="pw2" onblur="checkpw2();" /><label id="labelpw2"></label><br />


I am a: <br />
<input type="radio" name="status" value="fresh" /> Freshman<br />
<input type="radio" name="status" value="soph" /> Sophomore<br />
<input type="radio" name="status" value="jr" /> Junior<br />
<input type="radio" name="status" value="sr" /> Senior<br />



I am taking classes in the: <br />
<input type="checkbox" name="semester" value="fall" /> fall time<br />
<input type="checkbox" name="semester" value="spring" /> Spring time <br />



My favorite element is:
	<select name="element" id="element">
                <option value="">select one</option>
		<option value="fire">Fire</option>
		<option value="earth">Earth</option>
		<option value="water">Water</option>
		<option value="air">Air</option>
	</select><br />



*Birthday: <input type="text" id="BDay" name="Birthday" onblur="checkBDay();"/><label id="labelBDay"></label><br />



*E-Mail: <input type="text" id="email" name="Email" onblur="checkEmail();"/><label id="labelEmail"></label><br />


	<input type="submit" value="Submit" />
	<input type="reset" value="Clear" />

</form>

function isFormValid() 
{var userF = document.getElementById('FName').value;
	var userL = document.getElementById('LName').value;
	var userPW = document.getElementById('pw').value;
	var userPW2 = document.getElementById('pw2').value;
	var userBDay = document.getElementById('BDay').value;
	var userEmail = document.getElementById('email').value;
	var NameFormat = /^[A-Za-z]{2,12}$/;
	var PWFormat = /^[A-Za-z0-9{6,12}$]/;
	
	if (!NameFormat.test(userF))
		{
		alert("First Name is required and should only have letters. 2-12 letters max");
		return false;
		}
	if (!NameFormat.test(userL))
		{
		alert("Last Name is required and should only have letters. 2-12 letters max");
		return false;  
		}
	if (!PWFormat.test(userPW))
		{
		alert("Password is required and should only have letters and numbers. 6-12 letters max");
		return false; 
		}
	if (userPW != userPW2)
		{
		alert("Passwords do not match.");
		return false;
		}
	
}
                       
function checkFName()
{
	var userF = document.getElementById('FName').value;
	var elementF = document.getElementById('labelFName');
	var NameFormat = /^[A-Za-z]{2,12}$/;
	if (!NameFormat.test(userF))
		{
		elementF.innerHTML = "First Name is required and should only have letters. 2-12 letters max";
		elementF.style.color = "red";
		}
	else
		{
		elementF.innerHTML = "";
		elementF.style.color = "green"; 
		}
}

function checkLName()
{
	var userL = document.getElementById('LName').value;
	var elementL = document.getElementById('labelLName');
	var NameFormat = /^[A-Za-z]{2,12}$/;
	if (!NameFormat.test(userL))
		{
		elementL.innerHTML = "Last Name is required and should only have letters. 2-12 letters max";
		elementL.style.color = "red";
		}
	else
		{
		elementL.innerHTML = "";
		elementL.style.color = "green"; 
		}
}
function checkpw()
{
	var userPW = document.getElementById('pw').value;
	var elementPW = document.getElementById('labelpw');
	var PWFormat = /^[A-z0-9]{6,12}$/;
	if (!PWFormat.test(userPW))
		{
		elementPW.innerHTML = "Password is required and should only have letters and numbers. 6-12 letters max";
		elementPW.style.color = "red";
		}
	else
		{
		elementPW.innerHTML = "Valid Password";
		elementPW.style.color = "green"; 
		}
}
function checkpw2()
{
	var userPW2 = document.getElementById('pw2').value;
	var userPW = document.getElementById('pw').value;
	var elementPW2 = document.getElementById('labelpw2');
	if (userPW != userPW2)
		{
		elementPW2.innerHTML = "Passwords do not match.";
		elementPW2.style.color = "red";
		}
	else
		{
		elementPW2.innerHTML = "Passwords Match";
		elementPW2.style.color = "green"; 
		}
}

function validateForm()
{
var x=document.forms["regform"]["email_id"].value;
var atpos=x.indexOf("@");
var dotpos=x.lastIndexOf(".");


if (atpos<1 || dotpos<atpos+2 || dotpos+2>=x.length)
  {
  alert("Not a valid e-mail address");
  return false;
  }
}

function check(checkForm) 
{
    var fields = new Array("Name","Email Address", "Domain Name");

    var index = new Array(),k=0;
    for(var i=0;i<fields.length;i++)
    {
        var isFilled = false;
	    var c = document.getElementsByName(fields[i]);
	    for(var j = 0; j < c.length; j++)
	    if(!c[j].value == "")
	    {
	        isFilled = true;
	        c[j].className = "defaultColor";	        
        }
        else
        {
            c[j].className ="changeToRed";
        }  
	          
	    if(!isFilled)
	    {
            index[k++] = fields[i];
	    }
    }
    if(k.length!=0)
    {
	    joinComma = index.join(', ');
		alert('The field(s) corresponding to '+ joinComma + ' is/are not selected.');
		    return false;
    }
}

*Last Name:
<input type="text" id="Text27" name="Last Name" /><br />
<br />

*Email Address:
<input type="text" id="Text28" name="Email Address" />
@
<select id="Select5" name="Domain Name">
   <option></option>
   <option>hotmail.com</option>
   <option>yahoo.com</option>
</select>

<input id="Submit5" type="submit" value="Submit" onclick="return check(checkForm)"/>

function addOption()
        {   
            var newItem = prompt("Enter New Item");  
            
            if (!newItem == "")
            {
                var answer = confirm ("Are you sure you want to add? ") 
                if (answer)//if answer is true
                {
                    var lstBx = document.getElementById("lstBxEmail");
                      
                    // Now we need to create a new 'option' tag to add to MyListbox 
                    var newOption = document.createElement("option"); 

                    newOption.value = newItem; // The value that this option will have 
                    newOption.innerHTML = newItem; // The displayed text inside of the <option> tags
                       
                    // Finally, add the new option to the listbox 
                    lstBx.appendChild(newOption);             
                    //sort items in listbox in alpha order
                    arrTexts = new Array();

                    for(i=0; i<lstBx.length; i++) 
                    {
                        arrTexts[i] = lstBx.options[i].text;
                    }
                       
                    arrTexts.sort();
                    for(i=0; i<lstBx.length; i++)
                    {
                        lstBx.options[i].text = arrTexts[i];
                        lstBx.options[i].value = arrTexts[i];
                    }                     
                }
                                
                else
                {    
                    if(newItem)
                    {
                        alert("Key something to textbox please.");
                    }
                    
                    else
                        alert("Cancel choice.");
                }                    
            }
        }

                                <center><input id="Submit18" type="submit" value="Add Address" onclick="addOption()"/>

                                
                            <div>Address:</div>
                                <center>
                                <select id="lstBxEmail" name="listBoxEmail" multiple="multiple" style="width: 580px;">
                                      <option>Java</option>
                                      <option>PHP</option>
                                      <option>Perl</option>
                                      <option>Javascript</option>
                                      <option>C#</option>
                                      <option>Powershell</option>                                      
                                    </select>                              
                                </center>

<script src="http://code.jquery.com/jquery-latest.js"></script>
<script>
 $(window).ready(function() {
 	$("#responsecontainer").load("includes/inc-mess-jail.php", function(response, status, xhr) {
   
});
   var refreshId = setInterval(function() {
      $("#responsecontainer").load('includes/inc-mess-jail.php?randval='+ Math.random());
   }, 9000);
   $.ajaxSetup({ cache: false });
});
</script>

<tr>
    <td colspan="2">
        <div id="responsecontainer" align="center"></div>
    </td>
</tr>