Schema markup for generating a sitelinks search box in seach results

Hi,

I am a little stuck on part of the markup for generating a search box in search engine results, using the following code as an example, I'm not quite sure what I need to include at the end of the search results URL

<script type="application/ld+json">
{
"@context" : "http://schema.org",
"@type" : "WebSite",
"name" : "Elite SEM",
"url" : "http://mywebsite.com/",
"potentialAction" : {
"@type" : "SearchAction",
"target" : "http://mywebsite.com/?s={search_term}",
"query-input" : "required name=search_term"
}
}
</script>

I know I need to add searchresults.php? but what do I need to add at the end is it searchtext= or searchtext={search_term}

Cheers for any help offered

Jason

It's ok now Mike I have it sorted, yesterday must have been just too much strain on the brain