if(navigator.userAgent.indexOf('Mac') > 0 && navigator.userAgent.indexOf('Firefox') > 0)
  {document.write ('<style type="text/css">.fl{ margin-top:3px;} .jNiceRadio{margin-top:-2px;}#but_red{margin-left:230px;} #header_user{ position:absolute; margin-left:330px; margin-top:30px;}</style>');}