[flexcomponents] SetStyle with UI component

[learner]

Hi all,
Can I not use
setSytle("verticalAling","middle")
setSytle("horizontal","center")

with uiComponent

things like
mycomp extends UIComponent{

function mycomp (){
   super();
   setSytle("verticalAling","middle")
   setSytle("horizontal","center")          // this does not work :(
}


}

Please help
Regards
Ps