JavaScript - Math And Date Help

if ((word[0].match(/one|two|three|4|five|six|seven|eight|nine|ten/)) && (word[1].match(/plus|add/)) && (word[2].match(/one|two|three|4|five|six|seven|eight|nine|ten/))) {

document.result.result.value = "The answer is ?"; 
return true;}

Math.sin(Math.PI) // returns 1.2246467991473532e-16

<script type="text/javascript">
function countItDown(){
	var current=parseFloat(document.getElementById("currentsecondscount").value);
	var seconds=current;
	document.getElementById("debug").innerHTML="S "+current;
	var minutes=Math.floor(seconds/60);
	document.getElementById("debug").innerHTML+="<br>M "+minutes;
	var hours=Math.floor(minutes/60);
	document.getElementById("debug").innerHTML+="<br>H "+hours;
	var days=Math.floor(hours/24);
	document.getElementById("debug").innerHTML+="<br>D "+days;
	var remainingseconds=seconds-(minutes*60);
	document.getElementById("debug").innerHTML+="<br>RS "+remainingseconds;
	var remainingminutes=minutes-(hours*60);
	document.getElementById("debug").innerHTML+="<br>RM "+remainingminutes;
	var remaininghours=hours-(days*24);
	document.getElementById("debug").innerHTML+="<br>RH "+remaininghours;
	
	if(days<10){ days="0"+days; }
	if(remaininghours<10){ remaininghours="0"+remaininghours;}
	if(remainingminutes<10){ remainingminutes="0"+remainingminutes;}
	if(remainingseconds<10){ remainingseconds="0"+remainingseconds;}
	
	document.getElementById("days").innerHTML=days;
	document.getElementById("hours").innerHTML=remaininghours;
	document.getElementById("minutes").innerHTML=remainingminutes;
	document.getElementById("seconds").innerHTML=remainingseconds;
	document.getElementById("currentsecondscount").value=(current-1);
}
</script>
.......
<input type="hidden" id="currentsecondscount" value="<?=$seconds;?>" />
.......

function calculateLE(inputFieldId1, inputFieldId2, inputFieldId3, outputFieldId){
	var DBR;
	
	var input = document.getElementById(inputFieldId).value;
	
	APA = document.getElementById(fypremium).value;
	DBA = document.getElementById(dbp).value;
	LE  = document.getElementById(average_le).value;
	
	formula = document.getElementById(fypremium).value / document.getElementById(dbp).value = formula3;
	formula2 = document.getElementById(average_le).value * formula3;
	
	if { APA = "" } {
		document.getElementById(outputFieldId).value = "Error getting Annual Premium Amount";
	}
	else if { DBA = "" } {
		document.getElementById(outputFieldId).value = "Error getting Death Benefit Amount";
	}
	else if { LE = "" } {
		document.getElementById(outputFieldId).value = "Error getting Life Expectancy";
	}
	else {
		document.getElementById(outputFieldId).value = formula3;
	}
}

<input type="text" name="fypremium" id="fypremium" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">
<input type="text" name="dbp" id="dbp" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">
<input type="text" name="average_le" id="average_le" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">

function MM_changeProp(objId,x,theProp,theValue) { //v9.0
  var obj = null; with (document){ if (getElementById)
  obj = getElementById(objId); }
  if (obj){
    if (theValue == true || theValue == false)
      eval("obj.style."+theProp+"="+theValue);
    else eval("obj.style."+theProp+"='"+theValue+"'");
  }
}
function nextPhoto() {	
	MM_changeProp('fanThumbWrapOne','','left','-195px','DIV')
}
function prevPhoto() {	
	MM_changeProp('fanThumbWrapOne','','left','195px','DIV')
}

function calcPercent(item,sum){ // script element to calculate the percentage which is rounded to the nearest integer
     var items = Math.round( (item/sum)*100); // script element to get the percentage
return items;
}
     calcPercent(1, 3);

<script type="text/javascript">
    
    var num1;
    var num2;
    var num3;
    var ave_num=Math.round((num1 + num2 + num3) / 3);
    
    
//follow prompts to enter numbers and print average

    </script>

<script type="text/javascript">
<!--
var lastMonth;
var thisMonth;

function diff(form)
	{
	var difference;
	difference = lastMonth - thisMonth;
	form.Fdiff.value = difference;
	}

	
	
function SetLast(usuage)
{
lastMonth = usuage.value;
}

function SetThis(usuage2)
{
thisMonth = usuage2.value;
}

	// -->
</script>

<center>
<form method="post">
<TABLE border=3>
<tr>
<tr>
<td><p>Last Months <br /> Usuage</p></td>
<td><p>This Months <br /> Usuage</p></td>
<td><p>Difference</p></td>
<TD><INPUT TYPE=BUTTON ONCLICK="diff(this.form)" VALUE="Calculate"></TD>

</tr>
<tr>
</tr>
<td><p><input type=text name=lastMonth size="4" onchange="SetLast(usuage)"></p></td>
<td><p><input type=text name=thisMonth size="4" onchange="SetThis(usuage2)"></p></td>
<td><p><INPUT TYPE=text NAME="Fdiff" VALUE="" SIZE="6"></p></TD>
<TD><p></p></tr>
</tr>
</tr>
</table>
</form>
</center>


</center>

}
function calculate() {
	var f = document.forms[0], g, w, f, h, a, l, r;
	for (var i=0; i<(f.length-1); i++) {
		if (f.elements[i].selectedIndex == 0) {
			alert('Sorry, all options must be selected.');
			return false;
		}
	}
	g = f.g.options[f.g.selectedIndex].value;
	w = f.w.options[f.w.selectedIndex].value;
	h = f.h.options[f.h.selectedIndex].value;
	a = f.a.options[f.a.selectedIndex].value;
	l = f.l.options[f.l.selectedIndex].value;
	if (g == 'm') {
		r = ((66 + ((13.7 * w) / 2.2) + (5 * h * 2.54)) - (6.8 * a)) * l;
	} else {
		r = ((655 + ((9.6 * w) / 2.2) + (1.8 * h * 2.54)) - (4.7 * a)) * l;
	}
	alert(Math.round(r) + ' calories/day is what you require');
        alert(Math.round(r / f) + ' calories/day to burn);
	return false;