javascript function - error on multiple forms

Didn't work!

here is my complete javascript:

/* Highlight Row */
function highlight(id, currentClass, checkboxId)
{
   var checkbox_element = document.getElementById(checkboxId);
   var row_element = document.getElementById(id);
   row_element.className = checkbox_element.checked ? 'selected' : currentClass;
}
/* Check All */
function check_all()
{
var theemailformnum_checkboxes = document.forms["emailform"].elements.length;
   for(i = 0; i < theemailformnum_checkboxes; i++)
   {
      if(document.forms["emailform"].elements.type == 'checkbox')
      {
         document.forms["emailform"].elements.checked = true;
   
      }
   }
   highlight_all(theemailformnum_checkboxes);
}
/* Uncheck All */
function uncheck_all()
{
var theemailformnum_checkboxes = document.forms["emailform"].elements.length;
   for(i = 0; i < theemailformnum_checkboxes; i++)
   {
      if(document.forms["emailform"].elements.type == 'checkbox')
      {
         document.forms["emailform"].elements.checked = false;
      }
   }
   remove_highlight_for_all(theemailformnum_checkboxes);
}
/* Highlight All Rows (this happens when 'check_all' is triggered */
function highlight_all(theemailformnum)
{
   for(i = 1; i <= theemailformnum; i++)
   {
      document.getElementById('trid' + i).className = 'selected';
   }
}
/* Remove highlight for all Rows (this happens when 'uncheck_all' is triggered */
function remove_highlight_for_all(theemailformnum)
{
   for(i = 1; i <= theemailformnum; i++)
   {
      var initial_class = (i % 2) ? 'one' : 'two';
      document.getElementById('trid' + i).className = initial_class;
   }
}

and here is my form: (note, there are other forms in thiis page and if i delete those forms this javascript will work perfectly)

<form id="emailform" name="emailform">
 <table width="100%" border="0" cellspacing="0" cellpadding="3">
<cfloop query="GetEmails" startrow="#url.start#" endrow="#min(url.start+perpage-1, total)#">
  <tr id="trid#GetEmails.RecNum#" class="#oncheckvala#">
  
    <td width="22"><input onClick="JavaScript: highlight('trid#GetEmails.RecNum#', '#oncheckvala#', this.id);" type="checkbox" id="cb#GetEmails.RecNum#" name="id[]" value="#GetEmails.RecNum#"></td>
    <td width="150" align="left" valign="middle"><label for="cb#GetEmails.RecNum#">#FirstName# #LastName#(#GetEmails.RecNum#/#oncheckvala#/tr#GetEmails.RecNum#)</label></td>
    <td align="left" valign="middle">#EmailSubject#</td>
    <td width="150" align="left" valign="middle">#DateFormat(EmailDate, "ddd m/dd/yyyy")# #TimeFormat(EmailDate, "h:mm tt")#</td>
    <td width="50" align="left" valign="middle"><CFIF val(EmailAllSize) LT 1024>#val(EmailAllSize)# KB<CFELSE>#numberformat(val(EmailAllSize/1024))# MB</CFIF></td>
  </tr>
</table>
</cfloop>
</form>

on above code variable "oncheckvala" is change between "one" and "two" on each loop since my <TR> are dynamic and looping on each result.

also note that if I click on each check boxes they'll work fine and will perform the select, highligh and unhighlight function correctly but if I click on check all or uncheck all, that's where i'm getting the javascript error but again remember this will work if there are no other forms in this page.

here is my uncheck/check all command:

<a href="JavaScript: check_all(this.form);">Check</a> / <a href="JavaScript: uncheck_all(this.form);">Uncheck</a> All</a>

Thx for the reply. still not working