// precisa das funções 
// replace 
// splitstr
// isNumber

function isDate( data )
{
   var tdate, ad, rd, dm, tmpstr;
   dm = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
   data = replace(data, "-", "/");
   ad = splitstr(data, '/');

   if (ad.length != 3) return false;
   if((ad[1]>=1 && ad[1]<=12)==false) return false;	

   if(Math.floor(ad[2]/4)*4==ad[2]) dm[1] = 29;

   if(ad[2].toString().length != 4) return false;

   if((ad[0]>=1 && ad[0]<=dm[ad[1]-1])==false) return false;

   for(i=0; i<ad.length; i++)
      if ((isEmpty(ad[i])) || (!isNumber(ad[i])) || ((ad[i]<0))) return false;

   return true;

}