function validateEmail() {
        var v_email = document.getElementById("email");
        var v_message = document.getElementById("message");
        var v_subject = document.getElementById("subject");


        if( v_email.value == '' ) {
            alert("Please enter <E-Mail>.");
            v_email.focus();
              return false;
        }

        regexp = /^([a-zA-Z0-9_\-])+(\.([a-zA-Z0-9_\-])+)*@(((\[)?(((([0-1])?([0-9])?[0-9])|(2[0-4][0-9])|(2[0-5][0-5])))\.(((([0-1])?([0-9])?[0-9])|(2[0-4][0-9])|(2[0-5][0-5])))\.(((([0-1])?([0-9])?[0-9])|(2[0-4][0-9])|(2[0-5][0-5])))\.(((([0-1])?([0-9])?[0-9])|(2[0-4][0-9])|(2[0-5][0-5]))(\])?))|((([a-zA-Z0-9\-])+\.)+([a-zA-Z\-])+))$/gi;
        if( v_email.value.search(regexp) == -1 ) {
              alert("<E-Mail> is not valid.");
            v_email.focus();
             return false;
          }


        if( v_subject.value == '' ) {
            alert("Please enter <Subject>.");
            v_subject.focus();
              return false;
        }


        if( v_message.value == '' ) {
            alert("Please enter <Message>.");
            v_message.focus();
              return false;
        }

          return true;
    }