Form Validation

<script type="text/javascript">
function checkWholeForm(theForm) {
    var why = "";
    why += checkEmail(theForm.email.value);
    why += checkPassword(theForm.password.value);
    why += isEmpty(theForm.notempty.value);
    for (i=0, n=theForm.radios.length; i<n; i++) {
        if (theForm.radios[i].checked) {
            var checkvalue = theForm.radios[i].value;
            break;
        } 
    }
    why += checkRadio(checkvalue);
    why += checkDropdown(theForm.choose.selectedIndex);
    if (why != "") {
       alert(why);
       return false;
    }
return true;
}

function checkPassword (strng) {
 var error = "";
 if (strng == "") {
    error = "You didn't enter a password.
";
 }
    var illegalChars = /[\W_]/; // allow only letters and numbers
    if ((strng.length < 6) || (strng.length > 8)) {
       error = "The password is the wrong length.
";
    }
    else if (illegalChars.test(strng)) {
      error = "The password contains illegal characters.
";
    }
    
    else if (!((strng.search(/[a-z]+/) > -1)
  && (strng.search(/[A-Z]+/) > -1)
  && (strng.search(/[0-9]+/) > -1))) {
  error = "The password must contain at least one 
    uppercase letter, one lowercase letter,
    and one numeral.
";
  }
  
  var emailFilter=/^.+@.+\..{2,3,4,6}$/;
if (!(emailFilter.test(strng))) { 
       error = "Please enter a valid email address.
";
}
var illegalChars= /[\(\)\<\>\,\;\:\\\/\"\[\]]/
if (strng.match(illegalChars)) {
   error = "The email address contains illegal characters.
";

}
</script>

<form name="myForm" onsubmit="return validate_form(theForm);" method="post" action="editup.php">
<p>Epostadress<br />
<input type="text" name="email" value="<?php echo $info['email']; ?>"/><br />
<p>Lösenord<br />
<input type="password" name="pass" value=""/><br />
<p>Upprepa lösenord<br />
<input type="password" name="pass2" value=""/><br />

<input type='submit' value='Uppdatera användare' /></div><br /></p>
</form>