problem fix height and when scroll heigth area change?

hello i have problem with height. I fix it with:

function makeEditor() {
   var oFCKeditor = new FCKeditor( 'testfck' ) ;
   oFCKeditor.BasePath = "http://localhost/BeauteIntegrale/cpanel/" ;
   oFCKeditor.Config[ 'ToolbarLocation' ] = 'Out:xToolbar' ;
   oFCKeditor.Height = 500;  
    oFCKeditor.Weight = 230; 
    
   oFCKeditor.ReplaceTextarea() ;
}

when i enter a long text and scroll appear, the height change for to small and i dont want this.

see image attach

thanks for help me