[PD] messaging question

[Matthew Yee-King]

Hello list

I am trying to build a live capture and loop sampler in pd. 

I have 3 controls - start point, end point and record. 

Start point defines the point in the sampled array to start playback,
end point defines the point to end playback. Thus I can use sliders to
define the limits of a looping sample:

http://www.yeeking.net/pd/sampler2.png

The problem is that every time i move the sliders, i have to retrigger
all other numbers in the system to make the sample play back as i'd
expect. E.g. if i move the start point slider, I have to click the end
point slider then the 44100 message in the above image before it plays 
back as i want. 

I have connected a metro that bangs the sliders and the 44100 message, 
but this seems like a bad solution... 

http://www.yeeking.net/pd/sampler2_metro.png

Can anyone suggest how to update the 44100 message and end point slider
automatically?

cheers

matthew