var GuideSentence = 'Please enter keywords';
   function ShowFormGuide(obj) {
      // hyoji
      if( obj.value == '' ) {
         obj.value = GuideSentence;
         obj.style.color = '#808080';
      }
   }
   function HideFormGuide(obj) {
      // kesu
      if( obj.value == GuideSentence ) {
         obj.value='';
	        obj.style.color = '#808080';				
      }
   }