These are windows containing text boxes into which data can be entered and selection boxes and buttons of various types enabling options to be selected. When opening up a new dialog box or property sheet, most text boxes are likely to be blank and you will need to enter information into them. Sometimes, default values are already given. If data have already been entered, their values are shown and can be altered if you wish.

A dialog box usually contains instructions or specifications and usually relates to an action or process. 

 A property sheet contains data representing the properties of some component.

You can select a text box using the mouse pointer. In DRAINS you can also skip between text boxes or move to the next one using the Tab key at the left of your keyboard. The Enter key will not move the cursor between text boxes.

When you press the OK button to close a dialog box window, the program takes the displayed values into memory. Before it does this, it checks that important values are defined, and that values are within acceptable limits. Error messages are given if results are unacceptable, and you must change any incorrect values.

If you wish to close a dialog box without entering data, you can click the Close button. It is good practice to do this if you are reviewing data, as it prevents accidental changes being made.