This blog, I will explain how to check if the control have value or not using JQuery.

  1. <head id="Head1" runat="server">
  2. <title></title>
  3. <script src="JS/jquery-1.3.2.min.js" type="text/javascript"></script>
  4. <script type="text/javascript">
  5. $(document).ready(function () {
  6. $("#btnGet").click(function () {
  7. if ($("#TextBox1").val() != 0)
  8. { alert("text box is not empty"); }
  9. else {
  10. alert("text box is empty");
  11. }
  12. });
  13. });
  14. </script>
  15. </head>
  16. <body>
  17. <form id="form1" runat="server">
  18. <div style="padding-left: 100px">
  19. <br />
  20. <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
  21. <asp:Button ID="btnGet" runat="server" Text="Check If value Exists" OnClick="btnGet_Click" />
  22. </div>
  23. </form>
  24. </body>
Output

Then the Textbox has not value:

page at local host

And the Textbox has value:
textbox is not empty