I am in Malaysia now.
For your previous question: You should use
or if(_isPaused()){

For status of simulation. _pause() is an action to pause the simulation.
_play() us an action to start the simulation.

There are several ways to do what you want to do.
You can use polygon to plot the data
provide Hertz as x property, and Xmaxplot as y property.
Define ns=0 (interger) to record number of data point recorded.
When ever user click button, add action in the property field.
for example: Xmaxplot[ns]=xxx (name of the variable you want to save)
and ns=ns+1;
and set the number of polygon to ns;