弹出网页js

function openPopup() {
    window.open('https://example.com/popup.html', 'PopupWindow', 'width=600,height=400');
}

<div id="myModal" class="modal">
    <div class="modal-content">
        <span class="close-button">&times;</span>
        <p>这是一个模态对话框。</p>
    </div>
</div>

<script>
var modal = document.getElementById("myModal");
var span = document.getElementsByClassName("close-button")[0];

function openModal() {
    modal.style.display = "block";
}

span.onclick = function() {
    modal.style.display = "none";
}

window.onclick = function(event) {
    if (event.target == modal) {
        modal.style.display = "none";
    }
}
</script>

<style>
.modal {
    display: none;
    position: fixed;
    z-index: 1;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.4);
}

.modal-content {
    background-color: #fefefe;
    margin: 15% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
}

.close-button {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
}

.close-button:hover,
.close-button:focus {
    color: black;
    text-decoration: none;
    cursor: pointer;
}
</style>