@Sirraj 

So to make your logic work do this

1) create hidden variable of type String and hide it always using UI policy on form load

2) whenever user selects Yes set the hidden variable with Yes

3) when user changes value from Yes clear it

4) now use this hidden variable value in your script for comparision

Script like this

function onChange(control, oldValue, newValue, isLoading, isTemplate) {
	if (isLoading){
		return;
	}

	if(newValue == 'Yes'){
		g_form.setValue('hiddenVariable', 'Yes');
	}
	else if(newValue == 'No' ||  newValue == ''){
		g_form.clearValue('hiddenVariable');
	}

	if(g_form.getValue('hiddenVariable') == 'Yes' && newValue == 'No'){

		// your logic

	}

}

Regards
Ankur