function ChangeSelect(n)
{
var selectnum=n;
var kk = document.getElementById("zjlx").options;
for (var i=0; i<kk.length; i++) {
if (kk[i].value==selectnum) {
kk[i].selected=true;
break;
}
}
}
原文:http://www.cnblogs.com/baijin05/p/5040379.html