function ChgYear(y,m,d,I){
      
      M_ARRAY = new Array(31,28,31,30,31,30,31,31,30,31,30,31);
      
     
      M = parseInt(m);
      D = parseInt(d);
      D = D -1;
      if (((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)){
         M_ARRAY[1]=29;
      } 
      else {
         M_ARRAY[1] = 28;
      } 
      var DD = "SD" + I
      for (var i=document.addform.elements[DD].options.length-1;i>=0;i--){
	     document.addform.elements[DD].options[i]=null;
	  }
	  
	  document.addform.elements[DD].options.length=M_ARRAY[M-1];
      for (var j=0;j<M_ARRAY[M-1];j++){
        if (j==D){
	       op=new Option(j+1,j+1,D,D);
	    }
	    else {
	       op=new Option(j+1,j+1);
	    }   
	    document.addform.elements[DD].options[j]=op;
	  }   
   }