Script for Form validator in head causes error

Question

When I use the Window/Behaveiors/ to create a form validator, Dreamweaver CS5 puts script in the Head of page, and seems to work ok. But when I validate page with W3c it says there are errors with code and as Dreamweaver created this I have no idea what to do to put right, so could someone please help. This is code generated by Dreamweaver, all other pages have past with flying colors!
<script type="text/javascript">
function MM_validateForm() { //v4.0
  if (document.getElementById){
    var i,p,q,nm,test,num,min,max,errors='',args=MM_validateForm.arguments;
    for (i=0; i<(args.length-2); i+=3) { test=args[i+2]; val=document.getElementById(args[i]);
      if (val) { nm=val.name; if ((val=val.value)!="") {
        if (test.indexOf('isEmail')!=-1) { p=val.indexOf('@');
          if (p<1 || p==(val.length-1)) errors+='- '+nm+' must contain an e-mail address.\n';
        } else if (test!='R') { num = parseFloat(val);
          if (isNaN(val)) errors+='- '+nm+' must contain a number.\n';
          if (test.indexOf('inRange') != -1) { p=test.indexOf(':');
            min=test.substring(8,p); max=test.substring(p+1);
            if (num<min || max<num) errors+='- '+nm+' must contain a number between '+min+' and '+max+'.\n';
      } } } else if (test.charAt(0) == 'R') errors += '- '+nm+' is required.\n'; }
    } if (errors) alert('The following error(s) occurred:\n'+errors);
    document.MM_returnValue = (errors == '');
</script>

Answer 1

If the script is working fine in all browsers, you could put it in an external JS file and link to it, then the W3C validator won't find an error.
If you don't know already, learn about how to do this:
http://www.hypergurl.com/jsfiles.html