var AJAXForms;
var LastField = null;
var isIE = (navigator.appName == 'Microsoft Internet Explorer');

function CheckField(field) {
try {
AJAXForms = new XMLHttpRequest();
}catch(e){
AJAXForms = new ActiveXObject("Microsoft.XMLHTTP");
}

AJAXForms.onreadystatechange = processChange;
AJAXForms.open("GET", "ajax/ajax_register.php?cmd=register&field="+field.name+"&value="+field.value);
LastField = field.name;
AJAXForms.send(null);
}

function processChange() {
if (AJAXForms.readyState == 4) {
document.getElementById(''+LastField+'_1').innerHTML = AJAXForms.responseText;
document.getElementById(''+LastField+'_1').style.visibility = "visible";

}
}