detect Iframe on loadcomplete event?

I have an aspx page containing an iFrame in it. The iFrame loads a URL online开发者_JAVA技巧 and that URL online will then automatically be redirect to another page online too. What I'm trying to achieve is to make sure that the iFrame loaded all the content within it before redirect the user to another page on my site using Response.Redirect() from code behind.

What i'm looking for is something like this:

iframe1.onloadcomplete = function(){
  //redirect here
};

use this:

iframe1.onload = function(){
  //redirect here
};