AJAX - The Complete Reference

80 Part I: Core Ideas

var encodedVal;

if (!encodeURIComponent)

{

encodedVal = escape(val);

/* fix the omissions */

encodedVal = encodedVal.replace(/@/g,"%40");

encodedVal = encodedVal.replace(/\//g,"%2F");

encodedVal = encodedVal.replace(/\+/g,"%2B");

}

else

{

encodedVal = encodeURIComponent(val);

/* fix the omissions */

encodedVal = encodedVal.replace(/~/g,"%7E");

encodedVal = encodedVal.replace(/!/g,"%21");

encodedVal = encodedVal.replace(/\(/g,"%28");

encodedVal = encodedVal.replace(/\)/g,"%29");

encodedVal = encodedVal.replace(/'/g,"%27");

}

/* clean up the spaces and return */

return encodedVal.replace(/\%20/g,"+");

}

function createXHR()

{

try { return new XMLHttpRequest(); } catch(e) {}

try { return new ActiveXObject("Msxml2.XMLHTTP.6.0"); } catch (e) {}

try { return new ActiveXObject("Msxml2.XMLHTTP.3.0"); } catch (e) {}

try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) {}

try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) {}

return null;

}

function sendRequest(url, payload)

{

var xhr = createXHR();

if (xhr)

{

xhr.open("GET",url + "?" + payload,true);

xhr.onreadystatechange = function(){handleResponse(xhr);};

xhr.send(null);

}

}

function handleResponse(xhr)

{

if (xhr.readyState == 4 && xhr.status == 200)

{

var responseOutput = document.getElementById("responseOutput");

responseOutput.innerHTML = xhr.responseText;

}

}

function rate(rating)