If appears that ContentDocument is null. You can check that with the following code:
string code = "alert(document.getElementById('myIFrame').contentDocument != null)";
the Telerik team
Thank you for being the most amazing .NET community! Your unfailing support is what helps us charge forward!
We'd appreciate your vote for Telerik in this year's DevProConnections Awards. We are competing in mind-blowing 20 categories and every vote counts! VOTE for Telerik NOW >>