Windsreen Demister doesnt change over?

[smokin_vx]

hi guys, my air vent control on doesn;t seem to want to change the vents over *sigh*

does anyone know what it might be? Ive got part of the dash out to check behind the control knob to see if anything was loose but everything seems to be connected.

Is there something else I should check?

Help please its winter and i cant defog my windscreen, its driving me crazy!!

[smokin_vx]

sorted it now cheers

[Zharklm]

what was the cause?