WebView EvaluateJavascript

How is the best way to get the results of a javascript function that is called with EvaluateJavascript? For example:

string js = "function myFunction(value1, value2) { if value1 > value2 return true else return false}};";
js += "var x = myFunction(100, 50);";

webview.EvaluateJavascript(js);