Check attachment count using on submit client script

[RudhraKAM]

I have a requirement where i need to check if the catalog item have 2 attachments , if not it should not submit , 

i am able to check the attachment by using on submit client script on the catalog item but how and where to include the count ?

Can some one help me with that 

function onSubmit() {
//Type appropriate comment here, and begin script below

var proof = gel('sysparm_item_guid').value;
var att = new GlideRecord("sys_attachment");
att.addQuery("table_name", "sc_cart_item");
att.addQuery("table_sys_id", proof );
att.query(att);
if (!att.next()) {
alert("Please include the attachments");
return false;
}
return true;
}

[Mike Patel]

try below, ref - http://www.servicenowelite.com/blog/2017/5/12/service-portal-require-attachments

function onSubmit() {
	var count = getSCAttachmentCount();
	if(count <= 2) {
		alert('Please include the attachments');
		return false;
	}
}

[RudhraKAM]

even though i add 2 attachments its showing the alert 

[Mike Patel]

than change below

count < 2

[Mike Patel]

or 

if(count > 2) {
		alert('Please include the attachments');
		return true;
	}else{

alert('Please include the attachments');
		return false;
}