reaction controller problem


I'm trying to create a script that automatically makes a morph target react to a control object, I haven't finished yet, as I hit a wall, every time I execute the script(pressing the button) , I get an "unknown system exception".

the code creates a rollout that has a pick morph button with a field to input the channel name, another to pick the control object, and a "wire" button to make the morph react to the control object, every time i click the wire button i get the error.

global morphObjectchannel
global cont
global controlObject
rollout test "pick"
	pickbutton mbutton "Pick morph" tooltip:"pick an object with a morph modifier"
	pickbutton cbutton "pick controller object" tooltip:"pick the controller object"
	edittext channelno "Channel number:"
	button wire "Wire" tooltip:"wire a controller to the morph"
	on mbutton picked obj do
		-- check for a channel number
		if channelno.text == "" then
			-- if no channel number specified, ask the user to do so
			messagebox "please specify the morpher channel"
		--if there is a channel number
			--collect the channel number
			i = channelno.text as integer
			--put the morph object channel into the global morphObject
			try (morphObjectchannel = obj.morpher[i]) catch(messagebox "please pick an object with a morpher")
			--assign a reaction conroller top the morph channel
			morphObjectchannel.controller = float_reactor()
			cont = morphObjectchannel.controller 
	on cbutton picked obj do
		--TO DO: test for correct frozen object
		controlObject = obj
		Xlimit = obj.pos.controller[2].controller[1].controller.Limited_Controller__Bezier_Float.controller
		Zlimit = obj.pos.controller[2].controller[3].controller.Limited_Controller__Bezier_Float.controller
	on wire pressed do
		--print morphObjectchannel
		--print Xlimit
		---print Zlimit
		--print controlObject
		reactto cont Xlimit
		--move controlObject [25,0,0]
		--createReaction cont
		--move controlObject [-25,0,0]
createDialog test

please advice