Stopping onclick from firing when onclientclick is false?

Question

Is it possible to use the onclientclick property of a button to do a clientside check. If the check returns true, then fire the onclick event. If the clientside check returns false, don't fire the onclick event.

Is that possible?

UPDATE:

These 2 work:

Stops the form from submitting: OnClientClick="return false;" 

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Allows the form to submit: OnClientClick="return true;" 

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The next 2 do not work:

// in js script tag function mycheck() {     return false; }  // in asp:button tag OnClientClick="return mycheck();" 

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// in js script tag function mycheck() {     return true; }  // in asp:button tag OnClientClick="return mycheck();" 

It submits the form both times.

Why is that?

Answer 1

You want to add return inside OnClientClick after a function is called. Otherwise, the button will post back even if function returns false.

<asp:button ID="Button1" runat="server" OnClick="Button1_Click"      OnClientClick="return checkValidation()" Text="Submit" />  <script type="text/javascript">     function checkValidation() {         return confirm('Everything ok?');     } </script> 

Answer 2

Sure. If you use return false within your OnClientClick it will prevent any navigation from happening. So you're code would look like:

<asp:LinkButton runat="server" OnClientClick="if(!ValidatePage()) { return false;}" />