-1 down vote favorite function dropItems(idOfDraggedItem,targetId,x,y) { var targetObj = document.getElementById(targetId); // Creating reference to target obj var subDivs = targetObj.getElementsByTagName('DIV'); // Number of subdivs if(subDivs.length>3 && targetId!='capitals')return; // Sub divs exists on target, i.e. element already dragged on it. => return from function without doing anything var sourceObj = document.getElementById(idOfDraggedItem); // Creating reference to source, i.e. dragged object var numericIdTarget = targetId.replace(/[^0-9]/gi,'')/1; // Find numeric id of target var numericIdSource = idOfDraggedItem.replace(/[^0-9]/gi,'')/1; // Find numeric id of source if(numericIdTarget!=101