document.write ('<select name="ddd" class="sel02" id="sday">');

calendar = new Date();

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

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

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