How can retrieve the value of a label in PhoneGap?

I want to change the color of a label if another label says true.

I have tried this:

var color = ($(mobilelabel_596).text())
if (color===true) { 
$(element).css({'color':"#900"}); 
} 

But I keep getting errors that say "User transformation function exception. Reason: mobilelabel_596 is not defined".

Does anyone know what I did wrong?