function ltrim(str,char){
var pos = str.indexOf(char);
var sonstr = str.substr(pos+1);
return sonstr;
}
function rtrim(str,char){
var pos = str.lastIndexOf(char);
var sonstr = str.substr(0,pos);
return sonstr;
}
原文：http://www.cnblogs.com/toward-the-sun/p/4155087.html