Tech Help with some Javascript PayPal related.

[Smack dat]

I accept PayPal on my website and I would like to provide a coupon code for certain persons. As I understand it PayPal don't offer this directly through their website but it is possible.

I found this website https://www.paypal-knowledge.com/inf...1512&actp=LIST

Which says you can add the following code into the custom field (on PayPal)

<script type="text/javascript">
<!--
var discnt = 0; // no default percent discount

var coupons = new Array ( // place to put coupon codes
"coup1", // 1st coupon value - comma seperated
"coup2", // 2nd coupon value - add all you want
"coup3" // 3rd coupon value
);
var coupdc = new Array ( // place to put discounts for coupon vals
5,
10,
15
);
var coupval = "(blanket)"; // what user entered as coupon code

function ChkCoup () { // check user coupon entry
var i;
discnt = 0; // assume the worst
for (i=0; i<coupons.length; i++) {
if (coupval == coupons[i]) {
discnt = coupdc[i]; // remember the discount amt
alert ("Valid coupon number! \n\n" + discnt +
"% discount now in effect.");
return;
}
}
alert ("'" + coupval + "' is not a valid code!");
}

function Dollar (val) { // force to valid dollar amount
var str,pos,rnd=0;
if (val < .995) rnd = 1; // for old Netscape browsers
str = escape (val*1.0 + 0.005001 + rnd); // float, round, escape
pos = str.indexOf (".");
if (pos > 0) str = str.substring (rnd, pos + 3);
return str;
}

function ReadForm (obj1) { // apply the discount
var amt,des;
amt = obj1.baseamt.value*1.0; // base amount
des = obj1.basedes.value; // base description

if (discnt > 0) { // only if discount is active
amt = Dollar (amt - (amt * discnt/100.0));
des = des + ", " + discnt + "% dis, COUP = " + coupval;
}

obj1.amount.value = Dollar (amt);
obj1.item_name.value = des;
}
//-->
</script>

It then say you would add the following code to your website

<form action="https://www.paypal.com/cgi-bin/webscr" method="post" onsubmit="this.target = 'paypal';
return ReadForm (this);">
<input type="hidden" name="cmd" value="_cart" />
<input type="hidden" name="add" value="1" />
<input type="hidden" name="business" value="your_email_goes_here@your_site.com" />
<input type="hidden" name="item_name" value="2nd Item" />
<input type="hidden" name="amount" value="20.00" />
<input type="hidden" name="currency_code" value="USD" />
<input type="hidden" name="baseamt" value="20.00" />
<input type="hidden" name="basedes" value="2nd Item @20.00" />

Enter Coupon code [coup1] &gt;
<input type = "text"
size = "10"
name = "coupcode"; />

<input type="button" value="Check It"
onclick="coupval = this.form.coupcode.value;
ChkCoup();" />

Input quantity &gt;
<input type="text" name="quantity" value="1" size="4" />

<input type="image" src="addcart.gif" name="submit" alt="cart add" />
</form>

I haven't tried this but just need a simple "Pay Now" button that offers people the chance to input a code into a text field for a discount to be applied.
I tried the code in an online HTM viewer and it looked naff.

Anyone tell me if this is at all suitable for 2017 or can give me a better suggestion / code.