How do change the layout area sequential number in a layout

Hello all

I am using the transaction WLAMN Layout Maintenance New. In Change Layout Maintenance I would like to change the order of the layout modules in the layout by changing the area number. I cannot anyhow do this. Could somebody tell me how I can change the layout area numbe, i.e. how I can change the position of may layout modules in the layout.

Thanks in advance and best regards

Seija