JavaScript - Disabling And Enabling Button Based On Value From Php.

<p><input id="amount" name="amount" type="radio" value="125" />$125</p>
<p><input id="amount" name="amount" type="radio" value="75" />$75</p>
<p><input id="amount" name="amount" type="radio" value="50" />$50</p>
<p><input id="amount" name="amount" type="radio" value="25" />$25</p>
<p><input id="amount" name="amount" type="radio" value="other" /><input id="other_amount" name="other_amount" type="text" maxlength="7" style="width:100px;" /> Other ($10 minimum donation)</p>

<script type="text/javascript">
<!--

function get_radio_value()
{
if (document.donation.amount[4].checked)
	{
	document.getElementById('amount').value = document.donation.other_amount.value;
	alert(document.getElementById('amount').value);
	}
	
}
//-->
</script>

if (document.getElementById('ba' + roid.value + 'r' + roid2.value + 'c1').innerHTML = " ")
{
document.getElementsByName('open')[0].disabled=true;
}
else
{
document.getElementsByName('open')[0].disabled=false;
}

<table>
<tr>
<td>&nbsp;</td>
<td><label class="bold">Yes</label></td>
<td><label class="bold">No</label></td>
</tr>
<tr>
<td><label for="property_q1"> - Is this your house?</label></td>

<td><input name="property_q1" id="property_q1" type="radio" value="Yes" /></td>

<td><input name="property_q1" id="property_q1" type="radio" value="No" /></td>
</tr>
</table>

<br />

<div id="fine">It's fine, don't worry about filling it in.</div>
<div id="fill" style="display:none">Please fill in the form below.</div>
<table>
<tr>
<td>&nbsp;</td>
</tr>
<tr>
<td><textarea name="info" id="info" cols="60" rows="5"></textarea></td>
</tr>
</table>
<input type="submit" />

<form>
<input type="radio" name="website_status" value="exists"/> Exists
<input type="radio" name="website_status" value="purchase_required"/> Needs to be purchased

<select name="projects">
<option></option>
<option value="new_website">New Website</option>
<option value="website_redesign">Website Redesign</option>
</select>
</form>

<script type="text/javascript">
window.onload=function() {
  df=document.forms[0];
  df[1].disabled=true;
  df[0].onclick=function(){
  df[1].disabled=(df[1].disabled)?false:true;
  }
  df=document.forms[0];
  df[4].disabled=true;
  df[1].onclick=function(){
  df[4].disabled=(df[4].disabled)?false:true;
  }
    df=document.forms[0];
  df[5].disabled=true;
  df[4].onclick=function(){
  df[5].disabled=(df[5].disabled)?false:true;
  }
  df=document.forms[0];
  df[6].disabled=true;
  df[5].onclick=function(){
  df[6].disabled=(df[6].disabled)?false:true;
  }
  df=document.forms[0];
  df[9].disabled=true;
  df[6].onclick=function(){
  df[9].disabled=(df[9].disabled)?false:true;
  }
  df=document.forms[0];
  df[10].disabled=true;
  df[9].onclick=function(){
  df[10].disabled=(df[10].disabled)?false:true;
  }
  df=document.forms[0];
  df[12].disabled=true;
  df[10].onclick=function(){
  df[12].disabled=(df[12].disabled)?false:true;
  }
  df=document.forms[0];
  df[15].disabled=true;
  df[12].onclick=function(){
  df[15].disabled=(df[15].disabled)?false:true;
  }
  df=document.forms[0];
  df[18].disabled=true;
  df[17].onclick=function(){
  df[18].disabled=(df[18].disabled)?false:true;
  }
df = document.forms[0];  
df[2].onclick = function() {     
df[17].disabled = !df[17].disabled;     
df[18].disabled = !df[18].disabled;     
df[19].disabled = !df[19].disabled;
df[20].disabled = !df[20].disabled; } 

df[17].disabled = true; 
df[18].disabled = true; 
df[19].disabled = true;
df[20].disabled = true; 
 }
df = document.forms[0];  
df[3].onclick = function() {     
df[17].disabled = !df[17].disabled;     
df[18].disabled = !df[18].disabled;     
df[19].disabled = !df[19].disabled;
df[20].disabled = !df[20].disabled; } 

df[17].disabled = true; 
df[18].disabled = true; 
df[19].disabled = true;
df[20].disabled = true; 
</script>