Pass by references

I write some small program that uses xml. So I will use this function http://us3.php.net/manual/en/function.xml-parse-into-struct.php. Quote: "This function parses an XML file into 2 parallel array structures, one (index) containing pointers to the location of the appropriate values in the values array. These last two parameters must be passed by reference". What does it mean pass by reference in PHP? Thanks _________________________________________________________________ Is your PC infected? Get a FREE online computer virus scan from McAfee® Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963