function validate_form() {
               var arrError = [];
               if (document.form2.x_field145.value == 0) arrError.push("Please fill in the 'Full name' box.");
               if (document.form2.x_field146.value == 0) arrError.push("Please fill in the 'Email address' box.");
               if (document.form2.x_field149.value == 0) arrError.push("Please fill in the 'Comment' box.");
               if (arrError.length) {
                       alert(arrError.join("\n"));
                       return false;
               }
               return true;
       }