<div class="all-dropdown">

<input type="submit" value="TEKST OP KNOP" />
<div class="selectbox"><select>
<option value="URLINVULLEN">TEKST</option>
<option value="URLINVULLEN">TEKST</option>
</select></div>
</div>
<script>
function NavigateToSite(){
    var ddl = document.getElementById("resList");
    var selectedVal = ddl.options[ddl.selectedIndex].value;
    window.location = selectedVal;
}
</script>