How to use on blur event using c#?

Question

I want to use On Blur event in my project. but it doesn't work. this is my code:

code c#:
protected void xx()
    {
        TextBox2.Text = "zzzzzzzzzzzzzzzzzzz";
    }

 code design:
<asp:TextBox ID="TextBox1" runat="server" onblur="xx"></asp:TextBox>  
<asp:TextBox ID="TextBox2" runat="server" ></asp:TextBox> 

what is wrong?
by the way, I use visual studio 2010.

Answer 1

**aspx code:**    
<asp:TextBox ID="TextBox1" runat="server" onblur="validate();"></asp:TextBox>  
<asp:TextBox ID="TextBox2" runat="server" ></asp:TextBox> 

**javascript-code:**    
function validate() 
{
  var _textbox = $(this);
  $.ajax({
  url: "your page url here"(index.aspx) + "?FuncName=ValidateUserid&text="+_textbox.val(),
  context: document.body
}).done(function() {
  alert("you can do whatever you want here");
});
}


**aspx.cs code (server-side)**
protected void Page_Load()
{
  if(Request.QueryString["FuncName"].Equal("ValidateUserid"))
  { 
    string UserId = Request.QueryString["text"];
    //Put your database logic here.
  }
}

Dont forget to include your Jquery library in HEAD section of your ASPX page.