At Line — Sets a breakpoint at a specific line in a named procedure. You can make this type of breakpoint conditional; that is, it interrupts program execution only if a defined condition is satisfied. A breakpoint indicator appears in red in the shaded area to the left of each line in the source code pane where an At Line breakpoint is set. The following figure shows the New Breakpoint dialog box with the At Line tab.

On Error — Sets a breakpoint to interrupt program execution if an error occurs. The error condition can be general or specific. The following figure shows the New Breakpoint dialog box with the On Error tab.

Watchpoint — Sets a watchpoint to interrupt program execution when the value of a variable, buffer field, or attribute reference changes. The following figure shows the New Breakpoint dialog box with the Watchpoint tab.