Identifying the control that caused PostBack in ASP.NET

I was wondering, how to find out the actual control, that caused a Page submit (postback).
We can actually use the hidden __EVENTTARGET field, in the Pages request object to find out the control, that caused a post back. The following code will help...

private string GetControlThatPostedBack()
{
if(Page.IsPostBack)
{
//try to find the name of the postback control in the hidden __EVENTTARGET field
string controlName = Page.Request.Form["__EVENTTARGET"];
// if the string is not null, return the control with that name
if(controlName != null && controlName.Trim().Length > 0)
{
return Page.FindControl(controlName).ID;
}
}

//the above logic does not work for PostBack events fired by standard buttons.
//Still, we can find out the control, by looping through the Form's control collection
//and retrieving the control that submitted the page
foreach(string keyName in Page.Request.Form)
{
Control formControl = Page.FindControl(keyName);
if(formControl != null)
{
return formControl.ID;
}
}
return "";
}