function createRequestObject() {
    var ro;
    var browser = navigator.appName;
    if(browser == "Microsoft Internet Explorer"){
        ro = new ActiveXObject("Microsoft.XMLHTTP");
    }else{
        ro = new XMLHttpRequest();
    }
    return ro;
}

var http = createRequestObject();

function setReason(reason)
{
document.forms.special.reason.value = reason.value;
}

function getOrderDetails()
{

	document.getElementById('preview').innerHTML = "<img src=\"spinner.gif\">";

	var ordernumber = document.forms.special.ordernumber.value;

	var url = "invoice_special.php";
	var data = "sub=get&ordernumber=" + ordernumber;

	http.open("POST", url, true);
	http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    http.send(data);
	http.onreadystatechange = handleResponsePreview;

}

function handleResponsePreview() {
	
    if(http.readyState == 4){
	
        var response = http.responseText;

		var layers_replace = new Array();
		
		    layers_replace = response.split('*');	
					
			for(i=0;i<layers_replace.length;i++) {
					var update = new Array();
					update = layers_replace[i].split('|');

					if(update[0] == 'alert')
					{
					alert(update[1]);
					} 
					else if(update[0] == 'customername')
					{
					if(document.forms.special.name) { document.forms.special.name.value = update[1]; }
					}
					else if(update[0] == 'email')
					{
					if(document.forms.special.email) { document.forms.special.email.value = update[1]; }
					}
					else {
					if(document.getElementById(update[0])) { document.getElementById(update[0]).innerHTML = update[1]; }
					}
									
			}

    }
}