<script type="text/javascript">

function portal_openModalDialog() {
var options = SP.UI.$create_DialogOptions();
options.url = "/_layouts/Upload.aspx?List={327D2CF7-F385-4969-8973-E6FD3908A996}&RootFolder="; //Change the URL to the page you require.
options.title = "Title of Dialog Window";
options.dialogReturnValueCallback = Function.createDelegate(null, CloseCallback);
SP.UI.ModalDialog.showModalDialog(options);
}
function CloseCallback(result, value) {
if (result === SP.UI.DialogResult.OK) {
SP.UI.Notify.addNotification("Your request has been submitted");
}
if (result === SP.UI.DialogResult.cancel) {
SP.UI.Notify.addNotification("Request cancelled");
}
}
</script>

<button name="button" type="button" onclick="javascript:portal_openModalDialog();javascript:return false;" href="#" target="_self">Open Link</button>