IDL is a very powerful language that lets you manipulate data in all possibly imaginable way but also lets you create complex interfaces to perform these manipulations. Obviously, this power doesn't go without problems for the programmer. Being one of those (i've looked recently at my IDL directories and found that they contained about 40000 lines of code), I've come accross some of these problems. The purpose of this page is to present those to which I have found a solution. It may serve you when you will use IDL, but it will also help me remember how I solved these problems...