properties get value

Hello there,

I'm trying  to verify the value of a properties so I do that:

if(Pro.getValue("token").toString()==""){
	    	go();
    	}else{
    		getJson(Pro.getValue("token"));
    	}

With the property declared like that:

<property id="token" type="string"></property> 

But the test return false even if the properties is empty