function gowaver() {
		var block_val = document.getElementById("block_val");
                block_val.value = "";

		if (fileDialogOpen) {
			return;
		}
		if (connection == -1) {
			alert("Not connected to a terminal");
			return;
		}

		var block = document.getElementById("block");
		var apdu ="FF0000000FD4400160"+toHexDigit(block.value)+"FFFFFFFFFFFF"+uid;

		try {
		appendLog("Sending " + apdu);
			var response = exchange(connection, apdu);
		}
		catch(e) {
			appendLog("EXCEPTION " + lastException);
			throw e;
		}
		appendLog("Sent " + apdu);
		appendLog("Received " + response);

/*
		var apdu ="FF0000000FD440016101FFFFFFFFFFFF"+uid;
		try {
		appendLog("Sending " + apdu);
			var response = exchange(connection, apdu);
		}
		catch(e) {
			appendLog("EXCEPTION " + lastException);
			throw e;
		}
		appendLog("Sent " + apdu);
		appendLog("Received " + response);
*/
		var apdu ="FF00000005D4400130"+toHexDigit(block.value);
		try {
		appendLog("Sending " + apdu);
			var response = exchange(connection, apdu);
		}
		catch(e) {
			appendLog("EXCEPTION " + lastException);
			throw e;
		}
		appendLog("Sent " + apdu);
		appendLog("Received " + response);
		appendLog("Block: " + response.substring(8, 56));
                block_val.value = response.substring(8, 56);
	}