Question on Module Pool

Hi,

I have two input fields in a screen. They are "deptno-low" and "deptno-high". I am using these fields to input a range to display a list of departments in a second screen.

My Question is:-

1) I want to check that both of these fields are not initial using a "if condition".

2) deptno-low <= deptno-high.

Is it possible to accomplish the above 2 conditions in a single statement. If so, what is the code like?