document.getElementById('map').oncontextmenu = function (e) {
    e = e ? e : window.event;
    if (e.preventDefault) e.preventDefault(); // For non-IE browsers.
    else return false; // For IE browsers.
};

var mapOptions = {
    div: "map"
};

map = new OpenLayers.Map('map', mapOptions);
map.addLayer(new OpenLayers.Layer.OSM());

OpenLayers.Control.Click = OpenLayers.Class(OpenLayers.Control, {

    defaultHandlerOptions: {
        'single': true,
            'double': true,
            'pixelTolerance': 0,
            'stopSingle': false,
            'stopDouble': false
    },
    handleRightClicks: true,
    initialize: function (options) {
        this.handlerOptions = OpenLayers.Util.extend({}, this.defaultHandlerOptions);

        OpenLayers.Control.prototype.initialize.apply(
        this, arguments);
        this.handler = new OpenLayers.Handler.Click(
        this, this.eventMethods, this.handlerOptions);
    },
    CLASS_NAME: "OpenLayers.Control.Click"

});