function postUpgrade(){
    //$("#loading").show();
		var form_action = 'upgrade';
    
    var filtervars = {
				do_what:form_action,
        card_no:$("#txtupgrade").val()
        };

    $.ajax({
        type: "POST",
        url: "_ajax_files/upgrade_ajax.php",
        data: filtervars,
        dataType: "html",
        success: function(html){
        	if(html=="0"){
        		alert("Congratulations! You are eligible for an upgrade pricing. Click OK to receive your discount pricing.");
	        	document.joinform.isupgrade.value=1;
	        	document.joinform.upgradenumber.value=$("#txtupgrade").val();
	        	$("#up1").attr("class","second");
	        	$("#up2").attr("class","second");
	        	$("#up3").attr("class","second");
						$("#p1").attr("class","uhidden");
						$("#p2").attr("class","uhidden");
						$("#p3").attr("class","uhidden");
						document.joinform.submit();
					}else{				
						alert("The number is already submitted for upgrade.");
	        	document.getElementById("txtupgrade").value="";
	        }	

         	//$("#loading").hide();
        }
    });
}

function checkForm(){
	if(v_checkout.exec()){
		var str;
		str=new String();
		str=$("#txtupgrade").val();
		if(str.length==9 || str.length==12 || str.length==16)
			postUpgrade();					
		else
			alert("Please enter valid card number.");	
		return false;
	}else{
		return false;
	}
}