function validate_required(field,alerttxt)
{
with (field)
  {
  if (value==null||value=="")
    {
    alert(alerttxt);return false;
    }
  else
    {
    return true;
    }
  }
}

function validateEmail(elem)
{
   with (elem)
   {
       var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
       return emailPattern.test(value);
   }
}

function validate_form(formname)
{
    if (validate_required(document.formname.name,"Name must be filled out!")==false)
    {
      document.formname.name.focus();
      return false;
    } else
    if (validate_required(document.formname.email,"Email must be filled out!")==false)
    {
      document.formname.email.focus();
      return false;
    } else
    if (validateEmail(document.formname.email) == false)
    {
      document.formname.email.focus();
      alert("Please enter valid email address!");
      return false;
    } else
    if (validate_required(document.formname.phone,"Phone must be filled out!")==false)
    {
      document.formname.phone.focus();
      return false;
    } else
        return true;
}