thanks a lot for your answer. Your little script worked well.
Since I wanted to change the axis ticks with a script too, I needed to search a little more, but I also found a solution to my problem.
range ll=[%H]1!; // define range: active graph window, layer 1
ll.x.ticks = 5; //major and minor ticks of the x axis face to the inside of the graph
This works perfektly for me.