You don't say what application you are using. If you are using MS Word try:
1. click Format, Borders and Shading
2. select the Page Border tab
3. click the Options... button
4. assuming "Measure from:" is set to "Edge of page", increase the value of
"Bottom" - the maximum you can specify is 31.
5. If that doesn't help, change "Measure from:" to Text. With "Measure
from:" set to Text, the page border position can be adjusted by changing the
File, Page Setup, Margins.