function switch_controls(rad_val) {
	 if (rad_val.value == 2) {
     document.getElementById('min_sales').style.display = "none";
     document.getElementById('max_sales').style.display = "none";
     document.getElementById('lettings_min_sales').style.display = "block";
     document.getElementById('lettings_max_sales').style.display = "block";		 
		 		 
   }
	 
	 if (rad_val.value == 1) {
     document.getElementById('min_sales').style.display = "block";
     document.getElementById('max_sales').style.display = "block";
     document.getElementById('lettings_min_sales').style.display = "none";
     document.getElementById('lettings_max_sales').style.display = "none";		  	 		  
	 }
 }