var browser = {
  IE : !!(window.attachEvent && navigator.userAgent.indexOf("Opera") == -1),
  Opera : navigator.userAgent.indexOf("Opera") > -1,
  WebKit : navigator.userAgent.indexOf("AppleWebKit/") > -1,
  Gecko : navigator.userAgent.indexOf("Gecko") > -1
    && navigator.userAgent.indexOf("KHTML") === -1,
       
  getViewHeight : function(){
    return browser.IE ?
    // IE Cases
    // Test for IE 5-7 Quirks and IE 4
    (!(document.documentElement.clientHeight)
    || (document.documentElement.clientHeight == 0)) ?
    // IE 5-7 Quirks and IE 4 case
    document.body.clientHeight :
    //IE 6+ Strict Case
    document.documentElement.clientHeight:
    // Gecko and Other DOM compliant case
    window.innerHeight;
  },
       
  getViewWidth : function(){
    return browser.IE ?
    // IE Cases
    // Test for IE 5-7 Quirks and IE 4
    (!(document.documentElement.clientWidth)
    || (document.documentElement.clientWidth == 0)) ?
    // IE 5-7 Quirks and IE 4 case
    document.body.clientWidth :
    //IE 6+ Strict Case
    document.documentElement.clientWidth:
    // Gecko and Other DOM compliant case
    window.innerWidth;
  }
};