Automatic drawing of a line function quit

Microsoft Office Word 2007:
Up until today I have been able to hold down Ctrl and the - key, & after about 3 "-'s" if I hit Enter it would draw a line across the document. I wrongly clicked something in a little box with an arrow that came up, after I had drawn and then tried to delete the line. Now I can't draw the line automatically. How do I get this capability back?

Skootch

I do it so automatically that I think I may have used the Shift key, not the Ctrl key... I'm not sure. It's one of them....