Hi,

You can set width and height like below

frame1.height = 200px;
frame1.width = 200px;

also you can use below function to set size based of document content.

<script language="JavaScript">
function autoResize(id){
    var newheight;
    var newwidth;

    if(document.getElementById){
        newheight = document.getElementById(id).contentWindow.document .body.scrollHeight;
        newwidth = document.getElementById(id).contentWindow.document .body.scrollWidth;
    }

    document.getElementById(id).height = (newheight) + "px";
    document.getElementById(id).width = (newwidth) + "px";
}
</script>

I hope this will help you out.