How to call c# method from javascript function

Question

In my application I need to call aspx.cs method from javascript function call.

 

 I tried this one in

 

  <img id='img2' width="9px" border="0" src="plus.gif" onclick="MyHeader()"/> Header <div>

<asp:GridView ID="GrdHeader" runat="server" AutoGenerateColumns="false">

<Columns>

</Columns>

</asp:GridView></div>

 

My Javascript Function:

 

function MyHeader() {

PageMethods.BindHeaderGrid();

}

 

My code behined method:

 

[WebMethod]

public void BindHeaderGrid()

{

GrdHeader.DataSource = ds.Tables[0];

GrdHeader.DataBind();

}

 

But it is not call this function.