function foo1()
{
    var h2_1 = document.getElementById('h2_1');
    var h2_2 = document.getElementById('h2_2');
    var h2_3 = document.getElementById('h2_3');

    var services_list = document.getElementById('services_list');
    var clients_list = document.getElementById('clients_list');
    var project_data_year = document.getElementById('project_data_year');

    h2_1.style.color = 'red';
    h2_2.style.color = 'silver';
    h2_3.style.color = 'silver';

    services_list.style.display = 'block';
    clients_list.style.display = 'none';
    project_data_year.style.display = 'none';
}

function foo2()
{
    var h2_1 = document.getElementById('h2_1');
    var h2_2 = document.getElementById('h2_2');
    var h2_3 = document.getElementById('h2_3');

    var services_list = document.getElementById('services_list');
    var clients_list = document.getElementById('clients_list');
    var project_data_year = document.getElementById('project_data_year');

    h2_1.style.color = 'silver';
    h2_2.style.color = 'red';
    h2_3.style.color = 'silver';

    services_list.style.display = 'none';
    clients_list.style.display = 'block';
    project_data_year.style.display = 'none';
}

function foo3()
{
    var h2_1 = document.getElementById('h2_1');
    var h2_2 = document.getElementById('h2_2');
    var h2_3 = document.getElementById('h2_3');

    var services_list = document.getElementById('services_list');
    var clients_list = document.getElementById('clients_list');
    var project_data_year = document.getElementById('project_data_year');

    h2_1.style.color = 'silver';
    h2_2.style.color = 'silver';
    h2_3.style.color = 'red';

    services_list.style.display = 'none';
    clients_list.style.display = 'none';
    project_data_year.style.display = 'block';
}


function enable_block()
{
    var id = getVar('pref');
    if (id == 'services_list' || id == '') {document.getElementById('h2_1').style.color = 'red';};
    if (id == 'clients_list') {document.getElementById('h2_2').style.color = 'red';};
    if (id == 'project_data_year') {document.getElementById('h2_3').style.color = 'red';};

    if (id == '') {id = 'services_list';};
    document.getElementById(id).style.display = 'block';
};


function getVar(name)
         {
         get_string = document.location.search;
         return_value = '';

         do { //This loop is made to catch all instances of any get variable.
            name_index = get_string.indexOf(name + '=');

            if(name_index != -1)
              {
              get_string = get_string.substr(name_index + name.length + 1, get_string.length - name_index);

              end_of_value = get_string.indexOf('&');
              if(end_of_value != -1)
                value = get_string.substr(0, end_of_value);
              else
                value = get_string;

              if(return_value == '' || value == '')
                 return_value += value;
              else
                 return_value += ', ' + value;
              }
            } while(name_index != -1)

         //Restores all the blank spaces.
         space = return_value.indexOf('+');
         while(space != -1)
              {
              return_value = return_value.substr(0, space) + ' ' +
              return_value.substr(space + 1, return_value.length);

              space = return_value.indexOf('+');
              }

         return(return_value);
         }