asp:Textbox onblur() event in c#

Question

I want to call a method from code behind .aspx.cs file when the control leaves a textbox. It is not simple html textbox but <asp:Textbox runat="server / >
This method should be called at onblur() event of the textbox

Please provide me the code, that how to call a method on leaving the control regarding a textbox in c#

Waiting . . .
Regards!