function getAvailableNickname()
{
    var nickname=document.getElementById('SysWinView_SetNickname_TextBox1').value;
    PageMethods.GetAvailableNickname(nickname, OnNNSucceeded, OnNNFailed);  
    return false;
}  

function OnNNSucceeded(result, userContext, methodName) 
{  

    if (result.toString().startsWith('OK')) 
    {
        leaveSite=true;
        window.location = redirectAfterNicknameSet;    
    }
    else
    {
        document.getElementById('SysWinView_SetNickname_TextBox1').value = result;
        document.getElementById('SysWinView_SetNickname_Label1').innerHTML = "Nickname in use";
    }
} 

function OnNNFailed(error, userContext, methodName)  
{  
    alert('error');
}