<div id="spreadsheet"></div>
<script>
$("#spreadsheet").kendoSpreadsheet({
    sheets: [{
        name: "MySheet",
        rows: [{
            cells: [{
                value: "Underlined text",
                underline: true
            }, {
                value: "Normal text",
                underline: false
            }]
        }]
    }]
});
</script>