javascript function firing two times when clicking on map in mobile.

See more:

C#

C#4.0

jQuery-UI

In aspx page:

<div class="borderpadding">
            <div id="divMapCanvas" runat="server" style="width: 100%;">
            </div>
        </div>

IN CS PAGE::

divMapCanvas.Attributes.Add("OnClick", "javascript:return OpenDirectionsUrl('" + GetdirectionsURL + Storeaddress + "');");


In JavaScript Page:

function OpenDirectionsUrl(Url) {
    //alert("!");
    window.open(Url, "_blank");
    return false;
}

When i open page in desktop , Javascript function is firing ONE time . It's Fine

When i open page in Mobile, Javascript function is firing two times , I donno y?
Please help me....