need help on passing variable from asp.net to php

hi guys, it would be great if someone can help me to solve this problem, the case is as below,

Site1 -> running php with mysql,
Site2 -> running asp.net with access,

Now i need to do a search at site1(php) from site2(asp.net) and save detail on site2(asp.net) without leaving site1(php).

Is is possible and how to do it?
Using what programming script like DOM or SOAP?

please help...me...

jerry