function isIe6() {
	var bro=$.browser;
	if(bro.msie)
	{
		if(bro.version == 6.0)
			return true;
	}
	else {
		return false;
	}
}
function getPageSize() {  
            var xScroll, yScroll;  
            if (window.innerHeight && window.scrollMaxY) {    
                xScroll = window.innerWidth + window.scrollMaxX;  
                yScroll = window.innerHeight + window.scrollMaxY;  
            } else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac  
                xScroll = document.body.scrollWidth;  
                yScroll = document.body.scrollHeight;  
            } else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari  
                xScroll = document.body.offsetWidth;  
                yScroll = document.body.offsetHeight;  
            }  
            var windowWidth, windowHeight;  
            if (self.innerHeight) { // all except Explorer  
                if(document.documentElement.clientWidth){  
                    windowWidth = document.documentElement.clientWidth;   
                } else {  
                    windowWidth = self.innerWidth;  
                }  
                windowHeight = self.innerHeight;  
            } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode  
                windowWidth = document.documentElement.clientWidth;  
                windowHeight = document.documentElement.clientHeight;  
            } else if (document.body) { // other Explorers  
                windowWidth = document.body.clientWidth;  
                windowHeight = document.body.clientHeight;  
            }     
            // for small pages with total height less then height of the viewport  
            if(yScroll < windowHeight){  
                pageHeight = windowHeight;  
            } else {   
                pageHeight = yScroll;  
            }  
            // for small pages with total width less then width of the viewport  
            if(xScroll < windowWidth){     
                pageWidth = xScroll;          
            } else {  
                pageWidth = windowWidth;  
            }  
            arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight);  
            return arrayPageSize;  
 };
function getCurrentStyle (obj, prop) {     //IE中使用的是obj.currentStyle方法，而FF是用的是getComputedStyle 方法
   if (obj.currentStyle) {     //判断IE
        return obj.currentStyle[prop];    
   }    
    else if (window.getComputedStyle) {     //判断FF
        prop = prop.replace (/([A-Z])/g, "-$1");          
        prop = prop.toLowerCase ();       
         return document.defaultView.getComputedStyle (obj,null)[prop];    
    }     
    return null;  
}