js去掉左右空字符

String.prototype.Trim = function() 

{ 

return this.replace(/(^\s*)|(\s*$)/g, ""); 

} 

String.prototype.LTrim = function() 

{ 

return this.replace(/(^\s*)/g, ""); 

} 

String.prototype.RTrim = function() 

{ 

return this.replace(/(\s*$)/g, ""); 

}