How to make javascript function appear and play on site that i cannot change
   Here is the code that i would want to play on one page, imgur in particular, this will click the next button in the gallery i was wondering if i would just have to make my own extension or what

    function timeMsg()
    {
    var t=setTimeout("alertMsg()",3000);
    }
    function alertMsg()
    {
    alert("Hello");
    }

How to make javascript function appear and play on site that i cannot change
===

   Here is the code that i would want to play on one page, imgur in particular, this will click the next button in the gallery i was wondering if i would just have to make my own extension or what

    function timeMsg()
    {
    var t=setTimeout("alertMsg()",3000);
    }
    function alertMsg()
    {
    alert("Hello");
    }
