if (empty($_GET['avgrating']) && empty($_GET['location'])) //both field is empty will only filter by contract type
		{
			$sql="SELECT email,contract_type,phonenumber,postalcode FROM contractors WHERE contract_type='" . $_GET['contract_type'] . "'";
			echo "no opt ";
		}
		elseif (empty($_GET['location'])) // location field is empty and will ony filter by contract and rating
		{
			$sql="SELECT email,contract_type,phonenumber,postalcode FROM contractors WHERE contract_type='" . $_GET['contract_type'] . "' AND avgrating >='" . $_GET['avgrating'] . "'";
			echo "avg ";
		}
		elseif (empty($_GET['avgrating'])) //avgrating field is empty
		{
			$sql="SELECT email,contract_type,phonenumber,postalcode FROM contractors WHERE contract_type='" . $_GET['contract_type'] . "' AND location='" . $_GET['location'] . "'";
			echo "location ";
		}
		else //all field is provided
		{
			$sql="SELECT email,contract_type,phonenumber,postalcode FROM contractors WHERE contract_type='" . $_GET['contract_type'] . "' AND avgrating >='" . $_GET['avgrating'] . "' AND location='" . $_GET['location'] . "'";
			echo "avg + location ";
		}