JSFiddle - React, Tailwind, and code Playground

HTML

<tr>
    <td>Enter index value:</td>
    <td><input type="text" title="Enter Index#" id="ind" name="index"
               size="2" maxlength="2" /></td>
    <td><input type="text" id="bid" name="bid" value="start with this" /></td>
</tr>

JavaScript

$(document).ready(function() {
    var indexField = $("#ind");
    var bidArray = new Array();
    bidArray[0] = 'then update to this';
    bidArray[1] = 'or go for this';
    
    indexField.keyup(function() {
        var index = indexField.val();
        var bid = bidArray[index];
        
        if (bid !== undefined) {
            $("#bid").val(bid);
        }
    });
});