Calling Code-behind method from JavaScript in asp.net [duplicate]

I want to call a code behind method from JavaScript. Here is the scenario: the user will see messagebox in which he/she can select Yes or No. If user selects Yes from the messagebox i want to call the Delete method in code behind else i want to call the Insert method. here is JS:

 <script type="text/javascript" language="javascript">
        function Func() {
            var result = confirm('Are you sure you want to delete?');
            if (result) {
                //click ok button
                //Call the Delete Method
            }
            else {
                //click cancel button
                //Call the Insert method
            }
        }
</script>

here is how my code-behind look like:

protected void Delete()
{
  //delete code here
}
protected void Insert()
{
  //insert code here
}