Sample code for judging constellations by date

function xingzuo() { 
var start = 1901, date=document.getElementById("txtDay").value, month=document.getElementById("txtMonth").value;;
with (document.getElementById("txtXZ")){ 
if (month == 1 && date >=20 || month == 2 && date <=18) {value = " Aquarius: ";} 
if (month == 1 && date > 31) {value = "Huh?";} 
if (month == 2 && date >=19 || month == 3 && date <=20) {value = " Pisces ";} 
if (month == 2 && date > 29) {value = "Say what?";} 
if (month == 3 && date >=21 || month == 4 && date <=19) {value = " Aries ";} 
if (month == 3 && date > 31) {value = "OK. Whatever.";} 
if (month == 4 && date >=20 || month == 5 && date <=20) {value = " Taurus ";} 
if (month == 4 && date > 30) {value = "I'm soooo sorry!";} 
if (month == 5 && date >=21 || month == 6 && date <=21) {value = " Gemini ";} 
if (month == 5 && date > 31) {value = "Umm ... no.";} 
if (month == 6 && date >=22 || month == 7 && date <=22) {value = " cancer ";} 
if (month == 6 && date > 30) {value = "Sorry.";} 
if (month == 7 && date >=23 || month == 8 && date <=22) {value = " Leo ";} 
if (month == 7 && date > 31) {value = "Excuse me?";} 
if (month == 8 && date >=23 || month == 9 && date <=22) {value = " virgo ";} 
if (month == 8 && date > 31) {value = "Yeah. Right.";} 
if (month == 9 && date >=23 || month == 10 && date <=22) {value = " libra ";} 
if (month == 9 && date > 30) {value = "Try Again.";} 
if (month == 10 && date >=23 || month == 11 && date <=21) {value = " Scorpio ";} 
if (month == 10 && date > 31) {value = "Forget it!";} 
if (month == 11 && date >=22 || month == 12 && date <=21) {value = " Sagittarius ";} 
if (month == 11 && date > 30) {value = "Invalid Date";} 
if (month == 12 && date >=22 || month == 1 && date <=19) {value = " Capricorn ";} 
if (month == 12 && date > 31) {value = "No way!";} 
} 
}