How to block a user account after 3 invalied attempts

Hi folk's

Can any one help me out ,i done coding for if attempts 3 invalid user attempts by taking int static count variable,in that i have one drawback ,if one user made 2 invalid attempts ,and other user made 1st time invalid attempt and this account is blocking ,How can i rectify this problem can any one help me....

I placing my code below please check it out yar and tell me with one is the better option .....

static int count = 0;
    public void  count_log()//this my user count static function............
    {
        BAL_ClassLibrary.Rcm_service.LoginEntities get_login_details = login_values();
        if (count >2)
        {
            Loginbal objbal=new Loginbal();
             objbal.account_block(get_login_details);
             ScriptManager.RegisterClientScriptBlock(Page, Page.GetType(), "Result", "alert('*Your Account is blocked')", true);
               count = 0;

        }
        else
        {
            ScriptManager.RegisterClientScriptBlock(Page, Page.GetType(), "Result", "alert('*Invalied username or password')", true);
            count++;
        }

I am calling this function, when user made invalid user attempt to login...
and i incrementing the count value.....

Tags: C# (C# 4.0), ASP.NET