Embedding Custom font in aspx StyleSheet.css

I am trying to embed my new fonts with the StyleSheet.css as

@font-face {
   src:url(../Font/HelveticaNeueLTStd-Lt.otf);
   font-family: "HelveticaNeueLight";   
   font-style: normal;
}




.helveticaclass{
    color: Red;
    font-size:12px;
    font-family: "HelveticaNeueLight";


    }

And apply to the lable as

    <asp:Label ID="Label1" runat="server" Text="My Custom Text Helvetica font" EnableTheming="false" class="helveticaclass" ></asp:Label>


And my style Sheet located in 

Root
|
|
CSS
   |
   |
   StyleSheet.css

And the Font is located in

  Root
    |
    |
    Font
       |
       |
       Helveti开发者_开发问答caNeueLTStd-Lt.otf

But I'm unable to apply the font

Any solution or suggestion higly appreciated

Thanks in advance

You may take a look at this article which explains how to do cross browser font embedding.

@font-face {
   src:url(http://www.yoursite.com/font/HelveticaNeueLTStd-Lt.otf);
   font-family: "Helvetica Neue LT Std";   
   font-weight:bolder;
}

.whiteclass{
    font-family:"Helvetica Neue LT Std";
    font-weight:200;
    letter-spacing:1.4px;
    font-size:16px;
    color:#FFF;
    text-align:left;
}