Ajax Onclick Evaluation

function toggle_budget() {
if (window.XMLHttpRequest) {
http = new XMLHttpRequest();
} else if (window.ActiveXObject) {
http = new ActiveXObject("Microsoft.XMLHTTP");
}
handle = document.getElementById('budget');
var morebutton = document.getElementById('more');
var url = 'reward.php?';
if(handle.value.length > 0) {
var fullurl = url + 'budget='+handle.value;
http.open("GET", fullurl, true);
http.send(null);
http.onreadystatechange = statechange_reward;
morebutton.disabled=false;
}else{
document.getElementById('reward').innerHTML = '';
}
}

function statechange_reward() {
if (http.readyState == 4) {
var xmlObj = http.responseXML;
var html = xmlObj.getElementsByTagName('result').item(0).firstChild.data;
document.getElementById('reward').innerHTML = html+' £';
}
}
function GetDetails() {
var amount = document.getElementById('budget').value;
if(amount == '') {
alert('Please enter value to get More Deatails');
return false;
}else{
location.href='budget_reward/'+amount;
}
}


type="button" id="rwd" value="Get Reward" onclick="toggle_budget()"


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