function get_random()
{
    var ranNum= Math.round(Math.random()*2);
    return ranNum;
}

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

    var quote=new Array(4);
     quote[0]="images/0.jpg";
     quote[1]="images/1.jpg";
     quote[2]="images/2.jpg"; 
     quote[3]="images/3.jpg";
  
   document.getElementById('a').innerHTML = ("<table width=800 height=201><Tr><Td width=800 height=201 background='" + quote[whichQuote] +"' ><Td><tr></table>");

  }