function pz(obj1,obj2){
var L1 = obj1.offsetLeft;
var R1 = obj1.offsetLeft + obj1.offsetWidth;
var B1 = obj1.offsetTop + obj1.offsetHeight;
var T1 = obj1.offsetTop;
var L2 = obj2.offsetLeft;
var R2 = obj2.offsetLeft + obj2.offsetWidth;
var B2 = obj2.offsetTop + obj2.offsetHeight;
var T2 = obj2.offsetTop;
碰上返回true 碰不上返回false
if( R2<L1 || R1<L2 || B1<T2 || B2<T1 ){
return false; // 碰不上条件
}else{
return true; //碰上了
}
}