BUTTON with if else

My code is not working properly. The subtracting thing should only work if the text is 1 or higher.

Could somebody help me:

button1.onPress = function() { 
	if (voca_pg1.text > 0){
		voca_pg1.text=parseInt(voca_pg1.text)-10
		voca_pg2.text=parseInt(voca_pg2.text)-10
	}
	else if (voca_pg1.text < 0){
		voca_pg1.text = "1"
		voca_pg2.text = "11"
	}
};

When I click the button it goes -9 - -11

then when I click again it goes back to what I want 1 - 11