JsHttpRequest is a library for AJAX-based script creation compatible with the popular Prototype JS library. It could be used as a server part (PHP) for the Prototype JS, has a great cross-browser compatibility (IE 5.0+ including disabled ActiveX, Mozilla 1.7+, FireFox 1.0+, Opera 7.3+, and Safari); file uploads from user browser to the server; full support of PHP debug features (including fatal error handling); multi-dimensional data structures exchange (JSON analog); PHP session support; and optimal data loading method choosing (XMLHttpRequest, Microsoft.XMLHTTP, etc.) depending on the current browser. The interface is compatible with XMLHttpRequest.