function get_random()
{
    var ranNum= Math.floor(Math.random()*4);
    return ranNum;
}

function getaQuote()
{
   var whichQuote=get_random();

    var quote=new Array(4)
     quote[0]="I think I have DHMO fever. I'll should be ok in a couple hours.";
     quote[1]="I have a study session with my Hydrodynamics group.";
     quote[2]="Something came up, it's personal.";   
     quote[3]="I'm drowning over here!";
  
   document.form1.quotebox.value = quote[whichQuote];
  }