Fitting text alignment under roScreen

Function createOverlayBox(x, y,w,h,a) 

	black=&h000000FF
	font_registry = CreateObject("roFontRegistry")
	font = font_registry.GetDefaultFont(19, true, false)
	m.screen.DrawRect(x,y, w, h, &hFFFFFFFF)
	m.screen.DrawText(a.text,x+10,y+20,black,font)
	
End Function

in above code i am using roScreen and there is black ractangle is behind my text., which is drawing good but problem is that text is not fitting inside rect it's not wrapping here, because text length is bigger than rect.
is there any solution like imageCanvas(Text Attribute alignment)