You can use a Custom HTML Form element, write the JS code that you have and attach listener event on select box keyup.

what is the syntax in joget to attach listener event on select box

Hey Walter, 

Can you please elaborate it would be a great help, as I don't have any knowledge on the listener event

You can obtain the value of a form field either with normal JavaScript, or using the utility Javascript API#FormUtil

Hey Ander , I tried doing this by form util, but I was not successful. 

<script language="JavaScript" type="text/javascript">
    function singleSelectChangeText() {
        //Getting Value
        
 
        var selObj = document.getElementById("singleSelectTextDDJS");
        var selValue = selObj.options[selObj.selectedIndex].text;
        
        //Setting Value
        // document.getElementById("textFieldTextJS").value = selValue;



        if (selValue=="OBC"){
            window.alert("HEY YUR RYT");
        }
        else 
        {
            window.alert("byeeee");
        }
    }
</script>

This JavaScript code is perfectly running on Visual Studio, Fetching the data of the select box and displaying it in the text box, but in joget am not able to implement the code, my code is not fetching the select box data. Can you please have me out with. As this is the only place where I am tucked will be thankful if you provide me a solution for this.

Thank You!