var j=parseInt(Math.random()*31);
  j=(isNaN(j))?0:j;

function writeRightImages(){
  list = new Array();
  var where = "right";
// boilers
  list[list.length]='images/sub_' + where + '_boiler1.jpg';
  list[list.length]='images/sub_' + where + '_boiler2.jpg';
  list[list.length]='images/sub_' + where + '_boiler3.jpg';
  list[list.length]='images/sub_' + where + '_boiler4.jpg';
// certifications
  list[list.length]='images/sub_' + where + '_cert1.jpg';
  list[list.length]='images/sub_' + where + '_cert2.jpg';
// elevators
  list[list.length]='images/sub_' + where + '_elev1.jpg'; 
  list[list.length]='images/sub_' + where + '_elev2.jpg'; 
  list[list.length]='images/sub_' + where + '_elev3.jpg'; 
  list[list.length]='images/sub_' + where + '_elev4.jpg'; 
  list[list.length]='images/sub_' + where + '_elev5.jpg';
// engineers
  list[list.length]='images/sub_' + where + '_engineer1.jpg';
list[list.length]='images/sub_' + where + '_engineer1.jpg';   
     
  list[list.length]='images/sub_' + where + '_engineer3.jpg';   
  list[list.length]='images/sub_' + where + '_engineer4.jpg';   
  list[list.length]='images/sub_' + where + '_engineer5.jpg';   
// escalators
  list[list.length]='images/sub_' + where + '_esca1.jpg';   
  list[list.length]='images/sub_' + where + '_esca2.jpg';   
  list[list.length]='images/sub_' + where + '_esca3.jpg';   
  list[list.length]='images/sub_' + where + '_esca4.jpg';   
  list[list.length]='images/sub_' + where + '_esca5.jpg';
// explosives
  list[list.length]='images/sub_' + where + '_expl1.jpg';   
  list[list.length]='images/sub_' + where + '_expl2.jpg';   
// gauges
  list[list.length]='images/sub_' + where + '_gauge1.jpg'; 
  list[list.length]='images/sub_' + where + '_gauge2.jpg';   
// hands
  list[list.length]='images/sub_' + where + '_hands.jpg'; 
//pdas
  list[list.length]='images/sub_' + where + '_pda1.jpg';
  list[list.length]='images/sub_' + where + '_pda2.jpg'; 
  list[list.length]='images/sub_' + where + '_pda3.jpg'; 
  list[list.length]='images/sub_' + where + '_pda4.jpg'; 
// plans
  list[list.length]='images/sub_' + where + '_plans1.jpg';
  
  //alert("<img src='"+list[j]+"'>");
  document.write("<img src='"+list[j]+"'>");
}

function writeTopImages(){
  list = new Array();
  var where = "top";
// boilers
  list[list.length]='images/sub_' + where + '_boiler1.jpg';
  list[list.length]='images/sub_' + where + '_boiler2.jpg';
  list[list.length]='images/sub_' + where + '_boiler3.jpg';
  list[list.length]='images/sub_' + where + '_boiler4.jpg';
// certifications
  list[list.length]='images/sub_' + where + '_cert1.jpg';
  list[list.length]='images/sub_' + where + '_cert2.jpg';
// elevators
  list[list.length]='images/sub_' + where + '_elev1.jpg'; 
  list[list.length]='images/sub_' + where + '_elev2.jpg'; 
  list[list.length]='images/sub_' + where + '_elev3.jpg'; 
  list[list.length]='images/sub_' + where + '_elev4.jpg'; 
  list[list.length]='images/sub_' + where + '_elev5.jpg';
// engineers
  list[list.length]='images/sub_' + where + '_engineer1.jpg';
list[list.length]='images/sub_' + where + '_engineer1.jpg';   
     
  list[list.length]='images/sub_' + where + '_engineer3.jpg';   
  list[list.length]='images/sub_' + where + '_engineer4.jpg';   
  list[list.length]='images/sub_' + where + '_engineer5.jpg';   
// escalators
  list[list.length]='images/sub_' + where + '_esca1.jpg';   
  list[list.length]='images/sub_' + where + '_esca2.jpg';   
  list[list.length]='images/sub_' + where + '_esca3.jpg';   
  list[list.length]='images/sub_' + where + '_esca4.jpg';   
  list[list.length]='images/sub_' + where + '_esca5.jpg';
// explosives
  list[list.length]='images/sub_' + where + '_expl1.jpg';   
  list[list.length]='images/sub_' + where + '_expl2.jpg';   
// gauges
  list[list.length]='images/sub_' + where + '_gauge1.jpg'; 
  list[list.length]='images/sub_' + where + '_gauge2.jpg';   
// hands
  list[list.length]='images/sub_' + where + '_hands.jpg'; 
//pdas
  list[list.length]='images/sub_' + where + '_pda1.jpg';
  list[list.length]='images/sub_' + where + '_pda2.jpg'; 
  list[list.length]='images/sub_' + where + '_pda3.jpg'; 
  list[list.length]='images/sub_' + where + '_pda4.jpg'; 
// plans
  list[list.length]='images/sub_' + where + '_plans1.jpg';
  
  document.write("<img src='"+list[j]+"'>");
}