How to hide a map service layer?

ShaningYu

How to hide a map service layer?  For a map service with 2 dozens of layers, I want to hide one of them from the TOC.  Is there is an easy way to do it?  Thanks.

ShaningYu

I did another try by adding the function locally

function buildImageParameters (config) {
    var ip = new ImageParameters();
    for (var key in config) {
        if (config.hasOwnProperty(key)) {
            ip[key] = config[key];
        }
    }
    return ip;
}

The 'Not found' error is gone.  But with the defined  

layerIds: [1,2,3,4,5],

layerOption: ImageParameters.LAYER_OPTION_EXCLUDE

the layer 0 still in the TOC.  What's wrong in my code?  Thanks.