Calling C# function(code behind) from javascript function
 

Hi,

I have a problem in my code.
I am putting a image icon in my coe and want to call the code behind function Left_Click() on its OnClick() event.
But the Click event is generating after two times clicking.
and I have wriiten in the Page Load event
I want to write in PageLoad() method

as.Add.Attributes("onclick","javascript:Lef_Click();return false;);

For this I have to write a javascript function Lef_Click() and have to call that code behind function Left_Click() in it.
Is there any method to do this.
Please! Help me out.