_parameters").innerHTML = 'Axe des x : <select name="x_field" \
                    id="x_field-select" oninput="render ()"></select> Axe des y : <select name="y_field" id="y_field-select" \
                    oninput="render ()"></select> <button id="add_render_field" onclick="addRenderField ()">+</button>';
                    fieldOptions ([document.getElementById("x_field-select"), document.getElementById("y_field-select")]);
                } else if (graph_type === 'map') {
                    docume