function alternatecolor(id){ 
 if(document.getElementsByTagName){  
   var table = document.getElementById(id);  
   var rows = table.getElementsByTagName("tr");  
   for(i = 0; i < rows.length; i++){           
     if(i % 2 == 0){ 
       rows[i].className = "white";
     }else{ 
       rows[i].className = "lt_blue";
     }      
   }
 }
}
function alt_grays(){
	alternatecolor('alt_rowsA');
}