need help with this little ajax

[frank1002us]

i have copy and pasted this and it is working perfectly.
but i need to do this for multiple forms on one page.
as you can see i tried to do this by using
<?php echo $form_name; ?>
but since this value is done within a loop it does not work

<script language="Javascript">
function xmlhttpPost(strURL) {
    var xmlHttpReq = false;
    var self = this;
    // Mozilla/Safari
    if (window.XMLHttpRequest) {
        self.xmlHttpReq = new XMLHttpRequest();
    }
    // IE
    else if (window.ActiveXObject) {
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() {
        if (self.xmlHttpReq.readyState == 4) {
            updatepage(self.xmlHttpReq.responseText);
        }
    }
    self.xmlHttpReq.send(getquerystring());
}

function getquerystring() {
    var form     = document.forms['f1'];
 
	var formdata = '';
for (i = 0; i < <?php echo $form_name; ?>.elements.length; i++) { // loop through all the form elements
  formElem = <?php echo $form_name; ?>.elements[i];
  switch (formElem.type) {
    case 'text':
    case 'hidden':
    case 'password':
    case 'textarea':
      formdata += formElem.name + "=" + escape(formElem.value) + '&';
      break;
    case 'checkbox':
    case 'radio':
      if (formElem.checked===true) {
      formdata += formElem.name + "=" + formElem.value + '&';
      } // end of checked box or selected radio button
      break;
    case 'select-one':
      formdata += formElem.name + "=" + escape(formElem.options[formElem.selectedIndex].value) + '&';
      break; // it is possible to do this more succinctly, but then it does not work with older browsers
    default:
      formdata += formElem.name + "=" + escape(formElem.value) + '&'; // setting a default is all-important
  } // end switch
} // end for loop
formdata = formdata.substr(0,(formdata.length -1)); // snip off extra ampersand at the end of the string
    qstr = formdata ;  // NOTE: no '?' before querystring
    return qstr;
}

function updatepage(str){
    document.getElementById("result").innerHTML = str;
}

</script>

and here is my html

<input type="checkbox" name="sendto" value="true" /> Send a copy to my personal email address
<input value="Respond" type="button" onclick='JavaScript:xmlhttpPost("test.php")'>
<br/>Once posted can't be edited
</form>

[frank1002us]

i have made some progress and found the breakdown point
i do not get the value for "form_name"
here is my button

<input value="Respond" type="button" onclick='JavaScript:xmlhttpPost("test.php","c385982294011B")'>

and here is my function

function xmlhttpPost(strURL,form_name) {
    var xmlHttpReq = false;
    var self = this; 



    // Mozilla/Safari
formname=form_name;
    if (window.XMLHttpRequest) {
        self.xmlHttpReq = new XMLHttpRequest();
    }
    // IE
    else if (window.ActiveXObject) {
        self.xmlHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
    }
    self.xmlHttpReq.open('POST', strURL, true);
    self.xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    self.xmlHttpReq.onreadystatechange = function() {
        if (self.xmlHttpReq.readyState == 4) {
            updatepage(self.xmlHttpReq.responseText);
        }
    }

    self.xmlHttpReq.send(getquerystring(form_name));
}