function ValidateForm(f){

      with(f){
         if (isEmpty(_1_Name.value)) {
            alert("Please enter your name");
            _1_Name.focus();
            return false;
         }

		  if (isEmpty(_2_Telephone.value)) {
            alert("Please enter a contact phone number");
            _2_Telephone.focus();
            return false;
         }
 		if (isEmpty(_3_Email_From.value)) {
            alert("Please enter your Email Address");
            _3_Email_From.focus();
            return false;
         }

         if ( !isEmail(_3_Email_From.value) ) {
            alert("Please enter a valid Email Address.");
            _3_Email_From.focus();
            return false;
       }
         if (isEmpty(_4_Comments.value)) {
            alert("Please enter your Enquiry");
            _4_Comments.focus();
            return false;
         }
   	}
   return true;
 }