asp.net - Javascript confirm method not working -

i have button delete record in asp.net grid view

<asp:button id="btndelete" cssclass="btn btn-delete" tooltip="delete" runat="server" commandname="delete" commandargument='<%#eval("idjob")%>' usesubmitbehavior="false" onclientclick="return confirm('are sure?')" /> 

when click on rowcommand not fire. if remove onclientclick works.

can me please.

in place of onclientclick use onclick. onclick execute javascript when button clicked.

<asp:button id="btndelete" cssclass="btn btn-delete" tooltip="delete" runat="server" commandname="delete" commandargument='<%#eval("idjob")%>' usesubmitbehavior="false" onclick="return confirm('are sure?')" />