add_index = 1;
function addSpare() {
	var tr = document.createElement('tr');
	var td1 = document.createElement('td');
	var td2 = document.createElement('td');
	var td3 = document.createElement('td');
	td1.innerHTML = '<a href="javascript:void(0)" onclick="removeSpare(this)" style="text-decoration: none;">[&ndash;]</a>';
	td2.innerHTML = '<div class="itext_l"><div class="itext_r"><div class="itext_c"><input class="itext" type="text" name="spares[' + add_index + '][marking]" /></div></div></div>';
	td3.innerHTML = '<div class="itext_l"><div class="itext_r"><div class="itext_c"><input class="itext" type="text" name="spares[' + add_index + '][count]" align="middle"/></div></div></div>';
	tr.appendChild(td1);
	tr.appendChild(td2);
	tr.appendChild(td3);
	document.getElementById("spares_table").appendChild(tr);
	++add_index;
}
function removeSpare(obj) {
	var tr_to_remove = obj.parentNode.parentNode;
	document.getElementById("spares_table").removeChild(tr_to_remove);
}