using a where statement inside an if in PHP

So I got this part working no problem... But I want to use this with a variable.

So I only want it to do those things if the variable $one is equal to "Yes"

How can i put that though?

Or could I do this code a different way?

Like

If($one = 'Yes') {

then do the stuff to the pdf where $area->name = "1"

}

Can you add a where statement into an if to make that work?

if($area->name == "1"{
        $pdf->SetDrawColor(0, 255, 0);
        $pdf->SetLineWidth(1.0);
        $pdf->Line($x, $y, $x + $w, $y + $h);
        $pdf->Line($x, $y + $h, $x + $w, $y);
}