Any character in Java has to be a string enclosed with double quotes
Most probably I am aware of this thing.........
Line saparators are dependent of OS and are different in case of different OSs and are stored as system properties.
You can use
System.getProperty("line.separator"); to find the the Line-Saparator specific to that OS.
put \n in single quotes and use it like that <html>+'\n'.
Windows programs often process a '\n' separated text file correctly but there are some exceptions.
If it'll not work-
try this-
String ls=System.getProperty("line.separator");
out.println("<html>"+ls+"<head>");
it should work.....