C# String.Format token replacement for JavaScript

I use this for really simple token replacement. It may not work in all cases.

JavaScript Function:

function formatString(str)
{
    for(i = 1; i < arguments.length; i++)
    {
         str = str.replace('{' + (i - 1) + '}', arguments[i]);
     }
     return str;
}

Usage:

     var template= "<span>{0}bla bla{1}</span>";   
     var formatedHTML += formatString(template,"hello","world")
     $('#newHtml').html(formatedHTML);