function makeRandomNumber()
{
var text = "";
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
for( var i=0; i < 10; i++ )
text += possible.charAt(Math.floor(Math.random() * possible.length));
return text;
}
//another possible way is using Math.random()
Math.random().toString(36).substr(2,10)