function JSW_AJAX()
{
	this.getHTTPRequestObject = function()
	{
		// returns XML-Http-Request corresponding the browser
	}
}
function JSW_AJAXMicrosoft()
{
	JSW_AJAXMicrosoft.prototype = new JSW_AJAX();
	this.getHTTPRequestObject = function()
	{
		var requestObject = null;
		try 
		{ 
			requestObject = new ActiveXObject("Msxml2.XMLHTTP");
        } 
		catch (e) 
		{
            try 
            {
            	requestObject = new ActiveXObject("Microsoft.XMLHTTP");
            } 
            catch (e) 
            {
            	
            }
         }
		return(requestObject);
	}
}
function JSW_AJAXNetscape()
{
	JSW_AJAXNetscape.prototype = new JSW_AJAX();
	this.getHTTPRequestObject = function()
	{
		requestObject = new XMLHttpRequest();
	    if (requestObject.overrideMimeType) 
	    {
	    	requestObject.overrideMimeType('text/xml');
	    }
	    return(requestObject);
	}
}