Autolisp Programmer

I am wanting a few small autolisp programs developed for autocad. It is to draw simple shaped bench tops. I would like to input minimal dimensions such as length and width and have the drawing completed to about 80% from completion. All drawings are 2D only and consists of simple straight lines/rectangles. attached is an example of the what the result should look like. Please disregard the numbering of points as it was from my personal attempt at programming the drawing. I will have similar projects coming up in the near future of this work.