1<body style="margin:0px;padding:0px;overflow:hidden">
2 <iframe src="http://www.youraddress.com" frameborder="0" style="overflow:hidden;overflow-x:hidden;overflow-y:hidden;height:100%;width:100%;position:absolute;top:0px;left:0px;right:0px;bottom:0px" height="100%" width="100%"></iframe>
3</body>
1#IFRAME_ID {
2 width: 100%!important;
3 height: 100%!important;
4}
5<iframe src="http://www.youraddress.com" id="IFRAME_ID"></iframe>
6
7#####################
8If still not working you can try solution from on the solutions from the link
9https://stackoverflow.com/questions/819416/adjust-width-and-height-of-iframe-to-fit-with-content-in-it
1#IFRAME_ID {
2 width: 100%!important;
3 height: 100%!important;
4}
5<iframe src="http://www.youraddress.com" id="IFRAME_ID"></iframe>
1<body style="margin:0px;padding:0px;overflow:hidden">
2 <iframe src="http://www.youraddress.com" frameborder="0" style="overflow:hidden;height:100%;width:100%" height="100%" width="100%"></iframe>
3</body>