Client side validation of ASPX server controls with Best example

This is a simple validation control at the client side using JavaScript.  Here we have to perform the server side controls validation at the client-side using JavaScript. In below “RadiobuttonList” is server control and we had to perform validation at the client-side first once button click operation performed.

Why need it /Use of it:

The button click operation will not continue/Perform if you select the  “No” option in the radiobuttonlist. For this reason, we have to perform client-side validations using JavaScript for Asp.net server controls.

<td>  <div>   <asp:RadioButtonList ID="radiobuttonList1"       CssClass=" radiobuttonList1class" RepeatDirection="Horizontal"     RepeatColumns="2" runat="Server">     <asp:ListItem Text="Yes" Value="1"  Selected="True" />     <asp:ListItem Text="No" Value="0" />    </asp:RadioButtonList>  </div> </td> <td>                               <asp:Button ID="btnSubmit" Text="Submit" OnClientClick="return   btnsubmit_OnClientClick();" OnClick="btnSubmit_OnClick" runat="server"/> </td>

var flag = true;     function btnsubmit_OnClientClick()  {          if (Page_IsValid) //server-side validation          {             var IsRequest = false;             var radioObj = document.getElementById("<%=rbNeedBBAccount.ClientID %>");             var radioList = radioObj.getElementsByTagName('input');             for (var i = 0; i < radioList.length; i++) {                 if (radioList[i].checked) {                     if (radioList[i].value == 1) {                         flag = true;                     }                     else {                      alert("Ur Request for xx  can’t be processed, as Need for xx  account field is set to NO.");                         flag = false;                     }                 }             }         }         return flag;     }

Note:

1. If you are using more than one Validation Groups in page, so you need to explicitly specify the group.
2. Best reference URL for Asp.Net Validation using JavaScript:
1. http://praveenbattula.blogspot.in/2009/10/client-side-validation-of-aspx.html