function writediv(texte)
     {
     document.getElementById('pseudobox').innerHTML = texte;
     }

function verifPseudo(pseudo)
     {
     var regex = new RegExp("^[a-zA-Z0-9_]+$");
     if(pseudo != '')
               {
               if(!pseudo.match(regex))
                         writediv('<span style="color:#fd2d2d"><b><img src="imgs/icons/icons/cancel.png" alt="" style="vertical-align:middle;" width="16" height="16" /> '+pseudo+' :</b> This username contains illegal symbols. Type only letters, digits and underscores.</span>');
               else if(pseudo.length<2)
                         writediv('<span style="color:#fd2d2d"><b><img src="imgs/icons/icons/cancel.png" alt="" style="vertical-align:middle;" width="16" height="16" /> '+pseudo+' :</b> This username is too short.</span>');
               else if(pseudo.length>30)
                         writediv('<span style="color:#fd2d2d"><b><img src="imgs/icons/icons/cancel.png" alt="" style="vertical-align:middle;" width="16" height="16" /> '+pseudo+' :</b> This username is too long</span>');
               else if(texte = file('verifpseudo.php?pseudo='+escape(pseudo)))
                         {
          if(texte == 1)
               writediv(' <span style="color:#fd2d2d;"><b><img src="imgs/icons/icons/cancel.png" alt="" style="vertical-align:middle;" width="16" height="16" /> '+pseudo+' :</b> This username is already taken.</span>');
          else if(texte == 2)
               writediv(' <span style="color:#5ea948;"><b><img src="imgs/icons/icons/accept.png" alt="" style="vertical-align:middle;" width="16" height="16" /> '+pseudo+' :</b> This username is available.</span>');
          else
               writediv(texte);
                         }
               }

     }

function file(fichier)
     {
     if(window.XMLHttpRequest) // FIREFOX
          xhr_object = new XMLHttpRequest();
     else if(window.ActiveXObject) // IE
          xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
     else
          return(false);
     xhr_object.open("GET", fichier, false);
     xhr_object.send(null);
     if(xhr_object.readyState == 4) return(xhr_object.responseText);
     else return(false);
     }