var ipPattern = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/;
var ipArray = IPvalue.match(ipPattern);
if ((ipArray[1] != 137) || (ipArray[2] != 189)) {
	if ((ipArray[1] != 203) || (ipArray[2] != 188) || (ipArray[3] < 64) || (ipArray[3] > 67)){
	    if ((ipArray[1] != 202) || (ipArray[2] != 45) || (ipArray[3] < 184) || (ipArray[3] > 187)){
	        if ((ipArray[1] != 123) || (ipArray[2] != 255) || (ipArray[3] < 64) || (ipArray[3] > 127)){ 
                alert ("We are sorry that CU Net-TV can only be accessed within CUHK Shatin campus.");
                window.location = "http://www.cuhk.edu.hk";
            }
        }
    }
}
else if ((ipArray[3] == 128) || (ipArray[3] == 133) || (ipArray[3] == 134) || ((ipArray[3] >= 136) && (ipArray[3] <= 145)) || ((ipArray[3] >= 149) && (ipArray[3] <= 151))){
  window.location = "http://www.med.cuhk.edu.hk/cunettv/";
}
 
function viewChannel(channel){
 
 if ((ipArray[1] == 137) && (ipArray[2] == 189)) {
  if (((ipArray[3] >= 220) && (ipArray[3] <= 225 )) || (ipArray[3] >= 227)){
   window.location = "channel" + channel + "r.asx";
  }
  else if ((ipArray[3] >=204) && (ipArray[3] <=211)) {
                        alert ("We are sorry that CU Net-TV can only be accessed within CUHK Shatin campus.  It is not accessible by broadband VPN or dialup.");
  }
  else if ((ipArray[3] == 126) || (ipArray[3] == 127) || (ipArray[3] == 130) || (ipArray[3] == 131) || (ipArray[3] == 148)){
    alert ("We are sorry that CU Net-TV can only be accessed within CUHK Shatin campus.");
  }
  else
   window.location = "channel" + channel + ".asx";
 }
 else if ((ipArray[1] == 203) && (ipArray[2] == 188) && (ipArray[3] >= 64) && (ipArray[3] <= 67)){
   window.location = "channel" + channel + ".asx";
 }
 else if ((ipArray[1] == 202) && (ipArray[2] == 45) && (ipArray[3] >= 184) && (ipArray[3] <= 187)){
   window.location = "channel" + channel + ".asx";
 }
 else if ((ipArray[1] == 123) && (ipArray[2] == 255) && (ipArray[3] >= 64) && (ipArray[3] <= 127)){
   window.location = "channel" + channel + ".asx";
 }	 
 else
   alert ("We are sorry that CU Net-TV can only be accessed within CUHK network.");
}