AJAX and PHP

Chapter 6
}
{
// try to create XMLHttpRequest object
xmlHttp = new ActiveXObject(XmlHttpVersions[i]);
}
catch (e) {}
}
}
// return the created object or display an error message
if (!xmlHttp)
alert("Error creating the XMLHttpRequest object.");
else
return xmlHttp;
/* function that initializes the page */
function init()
{
// retrieve the input control for the keyword
var oKeyword = document.getElementById("keyword");
// prevent browser from starting the autofill function
oKeyword.setAttribute("autocomplete", "off");
// reset the content of the keyword and set the focus on it
oKeyword.value = "";
oKeyword.focus();
// set the timeout for checking updates in the keyword's value
setTimeout("checkForChanges()", 500);
}
/* function that adds to a keyword an array of values */
function addToCache(keyword, values)
{
// create a new array entry in the cache
oCache[keyword] = new Array();
// add all the values to the keyword's entry in the cache
for(i=0; i=0; i--)
{
// compute the current prefix keyword
var currentKeyword = keyword.substring(0, i+1);
// check to see if we have the current prefix keyword in the cache
if(oCache[currentKeyword])
{
// the current keyword's results already in the cache
var cacheResults = oCache[currentKeyword];
// the results matching the keyword in the current cache results
var keywordResults = new Array();
var keywordResultsSize = 0;
// try to find all matching results starting with the current prefix
for(j=0;j