I'm trying to change select tag options using this code in cefsharp
Browser.MainFrame.ExecuteJavaScriptAsync("document.getElementById(\"REG_CATSEQ\").selectedindex = 1;");
This is the select code
<select id="REG_CATSEQ" name="REG_CATSEQ" class="form-control select2">
<option value="">Select a value...</option>
<option value="1">تسجيل لأول مرة</option>
<option value="2">الواقعات الحياتية</option>
</select>
Looks like you have made a typo. Both languages are case sensitive. https://developer.mozilla.org/en-US/docs/Web/API/HTMLSelectElement/selectedIndex
Browser.MainFrame.ExecuteJavaScriptAsync("document.getElementById(\"REG_CATSEQ\").selectedIndex = 1;");