Click where you want to insert a blank underline.
On the Insert tab, in the Tables group, click Table.
Table command on the Insert tab
Click the upper-left box to insert a 1x1 table.
To change the length of the line, move the pointer over the end of the table until it becomes a resize pointer (double-headed arrow) , and then move the arrow right or left to lengthen or shorten the line.
Right-click the table, click Borders and Shading, and then click the Borders tab.
Under Setting, click None.
Under Style, click the line type, color, and width that you want.
In the diagram under Preview, click between the lower margin markers to add the bottom border. Make sure that only the bottom line is displayed.
Under Apply to, click Table, and then click OK.
