window.onresize = fix_height;

fix_height();

function fix_height() {

 var screen_height = get_screen_height();
 var frame_obj = document.getElementById("frame");
 frame_obj.height = screen_height - document.getElementById("bar").clientHeight - 4 + "px";

 return false;
}

function get_screen_height() {
 var myHeight = 0;

 if( typeof( window.innerWidth ) == 'number' ) {
 //Non-IE
 myHeight = window.innerHeight;
 } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
 //IE 6+ in 'standards compliant mode'
 myHeight = document.documentElement.clientHeight;
 } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
 //IE 4 compatible
 myHeight = document.body.clientHeight;
 }

 return myHeight;
}