function setBackground(){ 
   divMain = document.getElementById("text"); 
   y = 1; 
   divCollection = divMain.getElementsByTagName("div"); 
   for(i = 0; i < divCollection.length; i++) 
   if(divCollection[i].className == "material"){ 
      if(y % 2 == 0) divCollection[i].style.background = "#C0C08D"; 
      else divCollection[i].style.background = "#BABA87"; 
      y++; 
}}