JavaScript Validation Problem

Hi,

i have a form with javascript to make sure the content of the form is valid..

the script WORKED and did as it was supposed to until a added a new function

function validateForm(form)
{
  var fe = form.elements;
  //validate horse
    if (!requiredCheck(fe['dbhorsename'], 'Horse Name')) return false;
  //validate dob
    if (!requiredCheck(fe['dbDOB'], 'Date of Birth')) return false;
-this is the new line-    if (!validDob(fe['dbDOB'], 'Date of Birth')) return false;
  // ueln
    if (!requiredCheck(fe['dbUELN'], 'UELN')) return false;
    if (!validPhone(fe['dbUELN'], 'UELN')) return false;

  return true;
}

Code (markup):

the new function

function validDob(fieldObj, fieldName) {
    validDobRegEx = ^([1-9]|0[1-9]|[12][0-9]|3[01])\D([1-9]|0[1-9]|1[012])\D(19[0-9][0-9]|20[0-9][0-9])$
    if (!fieldObj.value.match(validDateRegEx)) {
        alert(fieldName+' is  not a valid date. Please correct and try again.');
        fieldObj.focus();
        return false;
    }
    return true;
}

Code (markup):

if i comment out the function valid Dob and comment out the code to call valid Dob the rest of the code works fine, with no problems. when i uncomment the function none of the validation works, not even the validation that worked previously.

anyone have any ideas what is causing this? thanks