JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
  <div class="someclass">
  <span>Tekeningen: </span>
    <label for="ValSR2">UIT:</label>
  <input dojoType="dijit.form.RadioButton" id="valSR2" name="group3" checked="checked" value="Show" onchange='Tekeningen(this);' value="Show" type="radio" />
    <label for="ValSlope2">AAN:</label>
 <input dojoType="dijit.form.RadioButton" id="valSlope2" name="group3" value="Hide" onchange='Tekeningen(this);' type="radio"/>
 </div>
</fieldset>

JavaScript

function Tekeningen(evt){
    if(evt.value === "Hide"){
        alert("removelayer");
    }
    else if(evt.value === "Show"){        
        alert("addlayer");
    }
}
window.Tekeningen = Tekeningen;