jQuery
1<script>
2 $(document).ready(function(){
3 $("#myModal").modal('show');
4 });
5</script>
1<img src="uk.png" alt="Continue to our UK site" onclick="setCountryCookie('UK')" />
1function setCountryCookie(country) {
2 document.cookie = `fppCountry=${country}`
3 countrySelector.hide();
4}
1window.location.href = 'https://www.yoursite.com';
pass a value in header to the new site, check for it on the other site and if present add a cookie
window.location.search
1"myCountry=UK; myName=Amna; myAge=31"
becomes
1["fppCountry=UK", " myName=Amna", " myAge=31"]
1matchString('myName is Amna', 'myName') // true
2matchString('myName is Amna', 'thyName') // false