function getWindowHeight() {
var windowHeight=0;
if (typeof(window.innerHeight)=='number') {
windowHeight=window.innerHeight;
}
else {
if (document.documentElement&&
document.documentElement.clientHeight) {
windowHeight=
document.documentElement.clientHeight;
}
else {
if (document.body&&document.body.clientHeight) {
windowHeight=document.body.clientHeight;
}
}
}
return windowHeight;
}