var myWidth = 0, myHeight = 0;

function get_size() {

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

}

function set_billview() {
        var header;
        var footer;
        var header_height;
        var footer_height;

         var version = 999; // sane browser
    if (navigator.appVersion.indexOf("MSIE") != -1)      // downgrade version number
      version = parseFloat(navigator.appVersion.split("MSIE")[1]);

        if(version < 7) {
                return;
        }else if(version < 9) {
                get_size();
                header=document.getElementById("mainPage");
                header_height=header.offsetTop+header.parentNode.offsetTop;
        }else{
                header=document.getElementById("header");
                header_height=header.offsetHeight;
        }

        footer=document.getElementById("footer");
        footer_height=footer.offsetHeight;

        var misc=80; // approx

        var target_height=myHeight-header_height-footer_height-misc;
        document.getElementById("billInfo").style.minHeight=target_height+"px";

}