JS Common Delete Space IP authentication and judgment characters exist code

In the application development will often encounter about IP, space in the string and determine whether there are some characters in the string, the following I provide the three utility function bar.

<script language= "Web Effects" type= "Text/javascript" >
String.prototype.trim = function ()
{
Return This.replace (/(^s*) | ( s*$)/g, "");
}
function checkstring (string1,string2) {
ii=0;
while (Ii<string1.length) {
if (String2.indexof (string1.substring (ii,ii+1)) ==-1) {return false;}
ii=ii+1;
}
}
function Isip (s)
{
if (s== "") return false;
var patrn=/^ ([01]?d?d|2[0-4]d|25[0-5]). ([01]?d?d|2[0-4]d|25[0-5]). ([01]?d?d|2[0-4]d|25[0-5]). ([01]?d?d|2[0-4]d|25[0-5]) $/;
if (!patrn.exec (s)) {return false;} else {return true;}
}
</script>-->