<div id="form1">
<div id="nc_captcha_container0" style="display:inline-block">
<input name="nc_captcha_hash" value="2e985d509b164fce8f7981b604f36c57" type="hidden">
<img name="nc_captcha_img" src="/netcat/modules/captcha/img.php?code=2e985d509b164fce8f7981b604f36c57">
</div>
</div>
<script>
window.onload = function () {
alert(document.querySelector("img[name='nc_captcha_img']").src);
}
</script>