// Check for empty value
function isEmpty(elementName) {
    return $(elementName).value == '';
}

//function to check valid email address
function isValidEmail(emailElementName){
    validRegExp = /^[^@]+@[^@]+.[a-z]{2,}$/i;
    emailValue = $(emailElementName).value;
    
    // search email text for regular exp matches
    if (emailValue.search(validRegExp) == -1) {      
      return false;
    } 
    
    return true; 
}