windows 7 - Micrososft Word creating a textbox with only top border

I want to create a textbox in microsoft word with only top border as we commonly find in place where signature is needed, like where we have a line above the word Signature.

Answer

A variation on Mr. J’s answer: insert a text box, remove the border, then insert a horizontal line by typing --- (three dashes) followed by Enter.  If there’s too much white space above the line, select the paragraph above the line and shrink it –– Ctrl+<, i.e., Ctrl+Shift+,, is a keyboard shortcut that does that.