There are thousands of tutorials, examples, code snippets, and explanations if you take a moment to search Google:
php with xml post
Also, you'll get a better response here if your subject line is descriptive, something like "
Help with php and xml post" instead of "
plz help me". A lot of people ignore the "
plz help me" type of posts because they give no idea of what kind of help you might need. I usually do.