JSFiddle - React, Tailwind, and code Playground

HTML

<tr>
        <td>
            <span id="MainContent_lblBusinessCenter" style="font-family:Open Sans;">House Center:</span></td>
        <td>
            <select name="ctl00$MainContent$ddlBusinessCenter" onchange="javascript:setTimeout(&#39;__doPostBack(\&#39;ctl00$MainContent$ddlBusinessCenter\&#39;,\&#39;\&#39;)&#39;, 0)" id="MainContent_ddlBusinessCenter" margin-Left="100px" style="font-family:Merriweather;height:30px;width:120px;">
	<option value="1">RA</option>
	<option selected="selected" value="2">HE</option>
	<option value="3">HT</option>
	<option value="4">LC</option>
	<option value="5">LO</option>
	<option value="6">WP</option>
	<option value="7">LN</option>
	<option value="8">CM</option>
	<option value="9">TB</option>
	<option value="10">VV</option>
	<option value="11">VZ</option>

</select><br />
        </td>
        
    </tr>





<table id="MainContent_gvKarakteristike" style="color:#333333;border-collapse:collapse;" cellspacing="0" cellpadding="4">
                <tbody><tr style="color:White;background-color:#507CD1;font-weight:bold;">
                    <th scope="col">Members</th><th scope="col">&nbsp;</th><th scope="col">Description</th>
                </tr><tr style="background-color:#EFF3FB;">
                    <td>
                                <span id="MainContent_gvKarakteristike_Karakteristike_0" mycustomattr="foo" margin-left="100px" style="display:inline-block;font-family:Georgia;height:30px;width:150px;">THK Total_Thickness</span>


                            </td><td>
                                <span id="MainContent_gvKarakteristike_Label_0" class="IDKarakteristike" margin-left="100px" style="display:inline-block;font-family:Georgia;height:30px;width:150px;">1</span>


                            </td><td>

                                 <select name="ctl00$MainContent$gvKarakteristike$ctl02$ddlOpis" id="MainContent_gvKarakteristike_ddlOpis_0" margin-left="100px" class="ddl" style="font-family: Georgia; height: 35px;...

JavaScript

$('#MainContent_ddlBusinessCenter').on('change', function () {
var value = $('#MainContent_ddlBusinessCenter').val();
alert(value);
});