Hello and welcome to the forum! Hard to answer such a brief question without further information, please provide the following: 1) iPad model; 2) iOS installed; and 3) What 'search box' are you talking about, e.g. Google, Search, or other?
For starters and in not already done, 'Reset' the device (hold down the HOME & ON-OFF buttons until the Apple logo appears, release both and allow the iPad to reboot; none of your data nor settings will be loss) and let us know if this maneuver helps. Good luck - Dave