function insertAuthor(i) {
 	var ind=document.getElementById('authorsTable').rows.length -2;
	if (ind <8) {
		var newRow = document.getElementById('authorsTable').insertRow(ind+1);

		var newCell1 = newRow.insertCell(0);
		var el1 = document.createElement('INPUT');
		el1.type = 'text';
		el1.name = 'firstnameAuthor[' + ind + ']';
		el1.id = 'firstnameAuthor' + ind ;
		el1.value = '';
		el1.size = '15';
		el1.maxlength ='30';
		el1.className = 'required';
		newCell1.appendChild(el1);

		var newCell2 = newRow.insertCell(1);
		var el2 = document.createElement('INPUT');
		el2.type = 'text';
		el2.name = 'lastnameAuthor[' + ind + ']';
		el2.id = 'lastnameAuthor' + ind ;
		el2.value = '';
		el2.size = '15';
		el2.maxlength ='30';
		el2.className = 'required';
		newCell2.appendChild(el2);

		var newCell3 = newRow.insertCell(2);
		var el3 = document.createElement('INPUT');
		el3.type = 'text';
		el3.name = 'emailAuthor[' + ind + ']';
		el3.id = 'emailAuthor' + ind ;
		el3.value = '';
		el3.size = '20';
		el3.maxlength ='100';
		el3.className = 'required validate-email';
		newCell3.appendChild(el3);
	}
}

function deleteAuthor() {
 	var ind=document.getElementById('authorsTable').rows.length -2;
	if (ind >1) {
		document.getElementById('authorsTable').deleteRow(ind);
	}
}