//让我来告诉你怎么写你想要的吧,看好:
(function(win){
var $ = function(obj1){return document.getElementById(obj1);},
paihang = function(obj1id) {$(obj1id).style.display='inline';},
hidden = function(obj1id) {$(obj1id).style.display='none';},
doit1 = function(){
var paihangxz_val1=$('paihangxz').value;
if (paihangxz_val1==1) {paihang('zdlph');hidden('djph');}
if (paihangxz_val1==2) {paihang('djph');hidden('zdlph');}
};
win.doit1 = doit1;
})(window);
jquery 提供防止冲突方法
jQuery.noConflict();