/* Styles for the popup window and overlay */ .popup { display: none; /* Hidden by default */ position: fixed; z-index: 1; left: 0; top: 0; width: 100%; height: 100%; overflow: auto; background-color: rgb(0,0,0); background-color: rgba(0,0,0,0.4); padding-top: 15%; } .popup-content { background-color: #fefefe; margin: 5% auto; padding: 20px; border: 1px solid #888; width: 80%; max-width: 600px; } .close-btn { color: #aaa; float: right; font-size: 28px; font-weight: bold; } .close-btn:hover, .close-btn:focus { color: black; text-decoration: none; cursor: pointer; } Side seamed Shoulder taping 52/48 Airlume combed and ring spun cotton/poly Size Chart × HOW TO MEASURE CHEST SIZE Measure around the fullest part of the chest, under the arms and around the shoulder blades. Men's Small Medium Large XL XXL XXXL Chest (in) 34-37 38-41 42-45 46-49 50-53 54-57 Length (in) 28 29 30 31 32 33 // Get the popup var popup = document.getElementById("popup"); // Get the button that opens the popup var btn = document.getElementById("popupBtn"); // Get the element that closes the popup var span = document.getElementsByClassName("close-btn")[0]; // When the user clicks the button, open the popup btn.onclick = function() { popup.style.display = "block"; } // When the user clicks on (x), close the popup span.onclick = function() { popup.style.display = "none"; } // When the user clicks anywhere outside of the popup, close it window.onclick = function(event) { if (event.target == popup) { popup.style.display = "none"; } }