Error: Syntax Error: Unexpected token 'else'

Hello! I'm brand new to Adobe After Effects and just used a mockup, but I'm getting a syntax error on line 1. I don't know much about codeing so I was hoping sombody smarter than me might know. Here's the error and code:

if(thisComp.layer("Color & Value Control").effect("Slider Control 01")("ADBE Slider Control-0001")>>0) thisComp.layer("Color & Value Control").effect("Percents Opacity")("ADBE Slider Control-0001") else 0;