calendar = new Date();

min_day = 1;
max_day = 31;
this_day = calendar.getDate();

document.write ('<select name="dDay">');

for(i=min_day;i<=max_day;i++) {
	
	if(i<10) {
		i2 = "0"+i;	
	} else {
		i2 = i;	
	}
	
	if(i == this_day) {
		document.write ('<option value="'+i2+'" selected="selected">'+i+'</option>');
	} else {
		document.write ('<option value="'+i2+'">'+i+'</option>');
	}
}

document.write ('</select>');