If you have not already done so, insert a chart by selecting it from the Insert menu, or double-click an existing chart to access the chart's configuration panel.
Select the Grid tab.
To hide the grid lines, clear the Show check box. To show the grid lines and configure grid line options, continue through the rest of the steps.
Select the Draw Lines at Major Ticks check box if you want a line at each major tick mark.
Select the Draw Lines at Minor Ticks check box if you want a line at each minor tick mark.
If you do not want lines drawn at major nor minor tick marks, make sure the check boxes for these options are cleared and enter the number of lines in the Number of Lines box.
To change the color of the grid lines, click the Grid Color button and select from the color palette.
To change the style of the grid lines, select an option from the Grid Style list box.