Why my Asp button doesn’t works even i added Onclick Event inside modal popup?

I have used ASP Button and added OnClick event in it, but while clicking the button it doesn’t works. Kindly help me out to sort out this!

HTML:

<asp:Button ID="Create_project" runat="server" Text="Create Project" OnClick="Create_project_Click"/>

Code Behind:

protected void Create_project_Click(object sender, EventArgs e)
    {
       Response.Write("Sucessfull");
    }

even i couldn’t insert the values to database!

“Note: I am using this button(Create_project) inside the Ajax:modalpopupextender”