function ValidateForm(f){

            with(f){
         if (isEmpty(name.value)) {
            alert("Please enter your Name");
            name.focus();
            return false;
         }

         if (isEmpty(email.value)) {
            alert("Please enter your Email Address");
            email.focus();
            return false;
         }

         if ( !isEmail(email.value) ) {
            alert("Please enter a valid Email Address.");
            email.focus();
            return false;
         }

if ( isEmpty(phone.value) ) {
            alert("Please enter your Phone Number");
            phone.focus();
            return false;
         }

         if (!isEmpty(phone.value)) {
	         if (!IsNumber(phone.value, true)) {
            	alert("Please enter only numbers for your Phone");
            	phone.focus();
            	return false;
         	}
         }

		  if (isEmpty(_4_Comments.value)) {
            alert("Please enter your comments or enquiry");
            _4_Comments.focus();
            return false;
         }

   	}
   return true;
 }