1. <%@ Page Language="C#" AutoEventWireup="true" CodeFile="MexLength.aspx.cs" Inherits="MexLength" %>
  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  3. <html xmlns="http://www.w3.org/1999/xhtml">
  4. <head runat="server">
  5. <title>Maximum length counter</title>
  6. <script language="JavaScript">
  7. function textCounter(field, countfield, maxlimit) {
  8. if (field.value.length > maxlimit) // if too long...trim it!
  9. field.value = field.value.substring(0, maxlimit);
  10. else
  11. countfield.value = maxlimit - field.value.length;
  12. }
  13. </script>
  14. </head>
  15. <body>
  16. <form id="Form1" name="myform" runat="server">
  17. <asp:TextBox ID="TextBoxMessage" runat="server" TextMode="MultiLine" Height="60px" onkeydown="textCounter(TextBoxMessage,LengthCount,25)" onkeyup="textCounter(TextBoxMessage,LengthCount,25)" ></asp:TextBox>
  18. <input readonly type="text" name="LengthCount" size="3" maxlength="3" value="25">
  19. </form>
  20. </body>
  21. </html>