JavaScript Basics

 

1. Getting Id of the Checkbox in JavaScript

The below code snippet demonstrates toggling : On selecting one checkbox the other checkbox if selected gets unselected and vice-versa.

    1: <script type="text/javascript" language=javascript>
    2:  
    3:     function fn() {
    4:         var checkbox = document.getElementById('<%= cbx1.ClientID %>');
    5:         if (checkbox != null && checkbox.checked == true) {
    6:             var checkbox2 = document.getElementById('<%= cbx2.ClientID %>');
    7:             if (checkbox2 != null && checkbox.checked == true) {
    8:                 checkbox2.checked = false;
    9:             }
   10:         }
   11:     }
   12:  
   13:     function fn2() {
   14:         var checkbox = document.getElementById('<%= cbx2.ClientID %>');
   15:         if (checkbox != null && checkbox.checked == true) {
   16:             var checkbox2 = document.getElementById('<%= cbx1.ClientID %>');
   17:             if (checkbox2 != null && checkbox.checked == true) {
   18:                 checkbox2.checked = false;
   19:             }
   20:         }
   21:     }
   22:  
   23: </script>
   24:  
   25: <asp:CheckBox ID="cbx1" onclick="fn()" runat="server" />
   26: <asp:CheckBox ID="cbx2" onclick="fn2()" runat="server" />