public String getColumnName(int i) throws Exception {
	   String colName = null;
	   if (i == 0) 
		   colName = "fileID";
	   else if (i == 1)
		   colName = "projID";
	   else if (i == 2)
		   colName = "format";
	   else if (i == 3)
		   colName = "fileName";
	   else if (i == 4)
		   colName = "location";
	   else 
		   throw new Exception("Access to invalid column number in courselist table");
	   
	   return colName;
   }