jqplot y-axis

Is it possible to remove the y-axis from the top two jqplot charts without affecting the x-axis?


Below is my code

$(document).ready(function(){  

//------------------------------------------Quadrant 1 (Top Left)
    var s2 = [200, 600, 700, 350];
    var ticks = ['>15', '11-15', '6-10', '0-5'];
     
    var plot2 = $.jqplot('testTarget2', [s2], {
        seriesDefaults:{
            renderer:$.jqplot.BarRenderer,
            rendererOptions: {fillToZero: true},
             pointLabels: {show: true}
        },
        series:[
            {label:'Airfare'}
        ],
            axesDefaults: {
        		showTicks: true,
        		showTickMarks: true       
    	},
        
        axes: {
            // Use a category axis on the x axis and use our custom ticks.
            xaxis: {
                renderer: $.jqplot.CategoryAxisRenderer,
                ticks: ticks
            },

    });


//------------------------------------------Quadrant 2 (Top Right)
    var s4 = [200, 600, 700, 350];
    var ticks = ['1-5', '6-10', '11-15', '>15'];
     
    var plot4 = $.jqplot('testTarget4', [s4], {
        seriesDefaults:{
            renderer:$.jqplot.BarRenderer,
            rendererOptions: {fillToZero: true},
             pointLabels: {show: true}
        },
        series:[
            {label:'Airfare'}
        ],          axesDefaults: {
        		showTicks: true,
        		showTickMarks: true       
    	},

        axes: {
            // Use a category axis on the x axis and use our custom ticks.
            xaxis: {
                renderer: $.jqplot.CategoryAxisRenderer,
                ticks: ticks
            }
        }
    });


//------------------------------------------Quadrant 3 (Bottom left)
    var s1 = [-700, -600, -250, -1000];
    var ticks = ['May', 'June', 'July', 'August'];
     
    var plot1 = $.jqplot('testTarget', [s1], {
        // The "seriesDefaults" option is an options object that will
        // be applied to all series in the chart.
        seriesDefaults:{
            renderer:$.jqplot.BarRenderer,
            rendererOptions: {fillToZero: true},
             pointLabels: {show: true}
        },
        series:[
            {label:'Airfare'}
        ],     
        axesDefaults: {
        showTicks: false,
        showTickMarks: false       
    },
        
        axes: {
            // Use a category axis on the x axis and use our custom ticks.
            xaxis: {
                renderer: $.jqplot.CategoryAxisRenderer,
                ticks: ticks
            },
        }
    });

//------------------------------------------Quadrant 4 (bottom right)
 var s3 = [-700, -600, -250, -1000];
    var plot3 = $.jqplot('testTarget3', [s3], {
        // The "seriesDefaults" option is an options object that will
        // be applied to all series in the chart.
        seriesDefaults:{
            renderer:$.jqplot.BarRenderer,
            rendererOptions: {fillToZero: true},
             pointLabels: {show: true}
        },
        series:[
           // {label:'Hotel'},
           // {label:'Event Regristration'},
            {label:'Airfare'}
        ],

            axesDefaults: {
        showTicks: false,
        showTickMarks: false       
    },

        axes: {
            // Use a category axis on the x axis and use our custom ticks.
            xaxis: {
                renderer: $.jqplot.CategoryAxisRenderer,
                ticks: ticks
            }

        }
    });


});

Here's the link to the actual page: jqplot 4 quadrant Chart