simple efs: want to plot (close-open)

[trapper]

I dont know much about efs so this is probably dumb question.

All I'd like to do is plot a simple histogram showing the value for (close -open) for each bar. The code I have is below but nothing plots:

var thisbar = (close-open);

function preMain(){
setStudyTitle("thisbar");
setPlotType(PLOTTYPE_HISTOGRAM);
}

function main(){
return thisbar;
}

What am I doing wrong/ not doing?

[ACM]

trapper
var thisbar = (close-open) should be changed to var thisbar = (close(0)-open(0)) and moved inside the main function. Once you implement these two changes it should work
Alex

[trapper]

Thanks Alex - thats it.