This is a simple example to show the difference between OnClick and OnClientClick Event of asp: Button
OnClick will work on server side ,
OnClientClick will execute on client side before control passed to server or C# code
OnClientClick will used to validate the controls like text box combo box etc...
If the Client Side code returns "TRUE" then it will go to server side code /"OnClick" Event will work
If the Client Side code returns "FALSE" then OnClick will not fired / Event will not work
<asp:Button id="test" Text="Click Here" runat="server" OnClientClick="validate()" onClick="Button1_Click" />
<asp:TextBox id="name" runat="server" />
function validate() {
var Firstname=document.getElementById('<%=name.ClientID%> ').value;
if(Firstname=="")
return false;
else
return true;
}
protected void Button1_Click(object sender, EventArgs e)
{
name.Text= "OnClick Work";
}