[TYPO3] Thanks page of Mail form, result page of search in new window

[Axon Communications]

Hi,
I am using typo3 4.0.0 on Linux. I am facing a tricky problem. The result
page of search appears in a new window and the thanks page on submission of
mail form also appears like that. These are not desirable. Similarly when we
add links, by default it target is new window. I want to make it same
window. The result page of search and the thanks page should also appear in
the same window. How can I achieve this? Please help me.
Thanks in advance for any help.
Axon.