String.prototype.httpHtml = function(){
var reg = /(http:////|https:////)((/w|=|/?|/.|//|&|-)+)/g;
return this.replace(reg, '<a target=_blank href="$1$2">$1$2</a>');
};

var s = " blank ";
s = s.replace(/^/s+(.*?)/s+$/, "");
alert(s);