function ClearText(e) {
    s1 = e.value;
    if (s1 == "email") {
        e.value = "";
        e.style.color = "Black"
    }
}
function ReplaceText(e) {
    s1 = e.value;
    if (s1 == "") {
        e.value = "email";
        e.style.color = "Grey"
    }
}
function GetKeyPress() {
    var key = window.event.keyCode;
    if (key == 13) {
        var obj = document.getElementById("btnNewsletter");
        obj.click();
    }
}

 //<asp:TextBox id="txtSearch" style="color:Gray;" onfocus="ClearText(this);" onblur="ReplaceText(this);" Text="Search Patras.travel" runat="server" />