JSFiddle - React, Tailwind, and code Playground

HTML

<SCRIPT>
function validar(obj){
    alert("Funciona");
    if this.value() > document.getElementById('cantidad2'){        
        
         document.getElementById('des2').focus();   
         alert("Malditop");
    }
}
</SCRIPT>


<form >
Line 1 Get <input type="val1" name="text1" id="des1" /> from <input type="val1" name="text1"  value="10" id="cantidad1"    /><br>
Line 2 Get <input type="val2" name="text2" id="des2" onchange="validar(this);" /> from <input type="val2" name="text2" id="cantidad2" value="10" /><br>
Line 3 Get <input type="val3" name="text3" id="des3" /> from <input type="val3" name="text3" id="cantidad3" value="10"/><br>
    
    <button type="submit">Submit</button>

</form>