JSFiddle - React, Tailwind, and code Playground
HTML
<select class="liste" size="5">
<option value="Minor">Minor</option>
<option value="Single">Single</option>
<option value="Married">Married</option>
<option value="Divorced">Divorced</option>
<option value="Widowed">Widowed</option>
</select>
<div id="absenden" style="display:none;">
<input type="submit" value="senden" />
</div>
JavaScript
jQuery("select.liste option").mosueup(function(){
alert("test");
if(jQuery("select.liste option:selected").length != 0){
jQuery("#absenden").css("display", "block");
}
else{
jQuery("#absenden").css("display", "none");
}
});