function check_un_ag(a)
{
if (document.RegAge.USERNAME.value != '' && document.RegAge.USERNAME.value.length >= 6)
{
	var objdoc;
	var ab1=new Array();
	var ab2=new Array();
    if (window.XMLHttpRequest) {
		var httpob=new XMLHttpRequest();
    } else if (window.ActiveXObject) {
		var httpob=new ActiveXObject("Microsoft.XMLHTTP");
        }
	httpob.open("POST","/areariservata/check_un_ag.asp?username=" + a ,false);
	httpob.send(null);
	ab1=httpob.responseText;
	ab2=ab1.split("^");
	alert(ab2[0]);
		if(ab2[1]=='found')
		{  document.RegAge.USERNAME.value='';  }
}
else
{
	alert("Inserire USERNAME\n(min. 6 caratteri)");
	document.RegAge.USERNAME.focus();
}
}