DateTime values on URL

Hello everyone! I have one php that calls another and passes a DateTime value like '2000-12-12 09:15:14' to the other script. When I run that with MS Internet Explorer it is OK but when I run it with Netscape it trims the time part of it. I think it is so because it has a blank space (ASCII 32) between the date and time part. So I need to replace the ASCII 32 values with %20 to pass it correctly. I have had the same difficultie when doing dlls for IIS under Windows NT. Once I created a function to replace blank spaces with %20 it was fixed. my url has something like this <href="scrp2.php4?DateTime=2000-12-12 09:15:14"> and I need to make it <href="scrp2.php4?DateTime=2000-12-12%2009:15:14"> with a %20 replacing the ASCII 32 blank space. How can I do that? Is there any function under PHP to do that? Thank you, Carlos Fernando.