Question

I tried using this code to obtain the var value using jQuery. For some reason name equals null or undefined, and I can’t seem to figure it out.

<asp:TextBox 
    ID="Text_Email" 
    runat="server" 
    CssClass="" 
    Width="234px">Email</asp:TextBox>

var name = $("#<%=Text_Email.ClientID%>").value; // name == undefined

Here is my main script:

$(document).ready(function () {
    $("#<%=send_info.ClientID%>").click(function () {
        // var name = document.getElementById("#<%=Text_Name.ClientID%>").value;
        var name = $("#<%=Text_Email.ClientID%>").value;
        var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

         if (reg.test(name) == false) {
             $(this).val("");
             $("#error_email_adress").removeClass('email_valid');
             $("#error_email_adress").addClass('email_invalid');
             return false;
         } else {
             $("#error_email_adress").removeClass('email_invalid');
             $("#error_email_adress").addClass('email_valid');
             alert("Message sent");
             return true;
         }
     });
 });

This part also confuses me. Why does this occur? Can someone explain to me why name is defined here?

$("#<%=Text_Email.ClientID%>").click(function () {
    var name = this.value;//name != undefined;
});

whereas here name is undefined

var name = $("#<%=Text_Email.ClientID%>").value; // name == undefined;

Thank you for any help.

Answer 1

jQuery does not have value but val() function for textbox,

Try this,

var name = $("#<%=Text_Email.ClientID%>").val();

Your code will be

$("#<%=Text_Email.ClientID%>").click(function () {
       var name = $(this).val();// you will get value in name by this statement.
});