Hostname should be mandatory based on priority and urgency is highest.otherthan that hostname field

[Sailaja Ponnala]

Hi sir

My question is that i have two fields priority and urgency .In priority there is drop down with highest normal,very high.Same way for urgency also i have highest , normal,very high. Now my requirement is if choose priority highest and urgency highest i should get pop up that hostname field should be filled mandatory and that field should come.Same way if i choose priority and urgency normal means that hostname field should be hide .for that I have gone through script but unable to fetch the answer.please help me

I have used this sil script
String var1=argv["priority"];
String var2=argv["custom field_10207];
If((var1=="Highest"&&var2=="Highest"))
{
Lfshowfieldmessage("custom field_17710","field required","Warning");
}
Else{
Lfhide("custom field_17710");
}

For this i have done live field function also
LfInstantHook({"priority","customfield_17710", customfield_10207"}," Hostname_mandatory_Sev.sil");
Lfwatch ("customfield_17710",{"priority","customfield_10207","custom field_17710"}, Hostname_mandatory_Sev.sil");

This want i have written i could get the requirement if choose priority and urgency high means that hostname field is not at all hiding..or else could please post related vedio please sir i am requesting . could please tell where i am mistaken.we have only power scripts could please help me what is exact script.