获取offsetTop和offsetLeft值的js代码(兼容

function offsetTop( elements ){ 
var top = elements.offsetTop; 
var parent = elements.offsetParent; 
while( parent != null ){ 
top += parent.offsetTop; 
parent = parent.offsetParent; 
}; 
return top; 
}; 
function offsetLeft( elements ){ 
var left = elements.offsetLeft; 
var parent = elements.offsetParent; 
while( parent != null ){ 
left += parent.offsetLeft; 
parent = parent.offsetParent; 
}; 
return parent; 
};