javascript drop down loop if statement

I have created 2 drop down menus, from and to, these include times starting from 8 > 22:00, however on submitting the form it is asking me to select a start time which has already been selected and confirmed by an alert option i have included, has really confused me!! any help appreciated.

craig

window.status='Loading contingency scripts - please wait...';
audit('Loading contingency scripts');
var conting={ i:0

,start:function(){
window.status='Loading form - please wait...';
var t='';
t+='<form name="frm_conting" id="frm_conting" onsubmit="return false;">';
t+='<table width="100%" cellspacing="1" cellpadding="0">';
t+='<tr><td>Date (DD/MM/YY):</td><td><input type="text" size="8" value="'+current_date+'" id="date"></td></tr>';

t+='<tr><td>Time Started:</td><td><select id="timefrom"><option></option>';
  for(h=8;h<23;h++){  
      for(m=0;m<46;m=m+15){  t+='<option value='+nb[h]+':'+nb[m]+'>'+nb[h]+':'+nb[m]+'</option>';  };
     };
t+='</select></td></tr>';

t+='<tr><td>Time Finished:</td><td><select id="timefrom"><option></option>';
  for(h=8;h<23;h++){  
  for(m=0;m<46;m=m+15){  t+='<option value='+nb[h]+':'+nb[m]+'>'+nb[h]+':'+nb[m]+'</option>';  };
     };

t+='</select><tr><td>Extension #:</td><td><input type="text" size="5" value="'+my.extension+'" id="staffid"></td></tr>';
t+='<tr><td>Desk ID:</td><td><input type="text" size="5" value='+my.deskid+' id="desk"></td></tr>';
t+='<tr><td>Number of calls:</td><td><input type="text" size="5" id="calls"></td></tr>';
t+='<tr><td>Avid ID:</td><td><input type="text" size="5" id="avid"></td></tr>';
t+='<tr><td><input type="button" value="Submit" onClick="conting.save()"></td>'; 
t+='</table>';
t+='</form>';

div_form.innerHTML=t;  
window.resizeTo(400,385);
window.status='';
}


,save:function(){
 alert (frm_conting.timefrom.value);
  var conting_date=frm_conting.date.value; 
   if(!isdate(conting_date)){alert("You have entered an incorrect date.");return false;};

var conting_timefrom=frm_conting.timefrom.value;  
 if(isNaN(conting_timefrom)){alert("You need to enter a starting time.");return false;}; 
 if(conting_timefrom.value>conting_timeto.value){alert("The time you have entered is after the finish time.");return false;}; 

var conting_timeto=frm_conting.timeto.value; 
 if(isNaN(conting_timeto)){alert("You need to enter a finishing time.");return false;}; 
 if(conting_timeto.value<conting_timefrom.value){alert("The time you have entered is after the finish time.");return false;}; 

var conting_staffid=frm_conting.staffid.value; 
 if(conting_staffid.l开发者_如何转开发ength!=5) { alert("You have entered an incorrect extension number.");return false;};

var conting_desk=frm_conting.desk.value; 
 if(conting_desk.length!=5) { alert("You have entered an incorrect desk ID.");return false;}; 

var conting_calls=frm_conting.calls.value; 
 if(isNaN(conting_calls)){alert("You have not entered amount of calls.");return false;};

var conting_avid=frm_conting.avid.value; 
 if(isNaN(conting_avid)){alert("You have entered an incorrect avid ID.");return false;};
 if(conting_avid.length!=5) { alert("You have entered an incorrect avid ID.");return false;}; 

 conn.open(db["contingency"]);
 rs.open("SELECT MAX(prac_id) FROM practice",conn);
var prac_id=rs.fields(0).value+1;
 rs.close();
 rs.open("INSERT INTO practice (prac_id, prac_staffid, prac_date, prac_timefrom, prac_timeto, prac_extension, prac_desk, prac_calls, prac_avid) VALUES (1, 2, 3, 4, 5, 6, 7, 8, 9)",conn); 
 conn.close();



}


};
 window.status='';

enter code here

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Well one of your problems is that you're using the same ID on both select lists. It's hard to judge the rest of the problems given the code.

t+='<tr><td>Time Started:</td><td><select id="timefrom"><option></option>';
  for(h=8;h<23;h++){  
      for(m=0;m<46;m=m+15){  t+='<option value='+nb[h]+':'+nb[m]+'>'+nb[h]+':'+nb[m]+'</option>';  };
     };
t+='</select></td></tr>';

t+='<tr><td>Time Finished:</td><td><select id="timefrom"><option></option>';
  for(h=8;h<23;h++){  
  for(m=0;m<46;m=m+15){  t+='<option value='+nb[h]+':'+nb[m]+'>'+nb[h]+':'+nb[m]+'</option>';  };
     };

---

<option value='+nb[h]+':'+nb[m]+'>'

The js save routine will fail whenever the value is not a number (isNaN). The value has a colon in it, hence it's never a number. You don't need to check isNaN, because it's a drop down, so you control what is entered there, unlike a text box where you might use isNaN to be sure the user typed in a number.