Selecting checkbox that changes name every run

Here's a few examples of using XPath to highlight the control not using full id name,

function test1()
{
    // URL https://www.w3schools.com/html/tryit.asp?filename=tryhtml_id_css
    var page = Aliases.browser.Page("https://www.w3schools.com/html/tryit.asp?filename=tryhtml_id_css").FindElement("#iframeResult");
    var item = page.FindElement("//*[@id='myHeader']");
    Sys.HighlightObject(item);
    var item = page.FindElement("//*[@id[starts-with(., 'my') and string-length() > 3]]");
    Sys.HighlightObject(item);
    var item = page.FindElement("//*[starts-with(@id, 'my')]")
    Sys.HighlightObject(item);
}