Time的判断

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function keypress(obj)
{
 var kindex = window.event.keyCode;
 if(kindex < 48 || kindex >57)
 {
  window.event.keyCode = 0;
  return;
 }
 debugger;
 var ovalue = obj.value;
 var re = document.selection.createRange();
 re.text = String.fromCharCode(kindex);
 var nvalue = obj.value; 
 re.text = "";
 
 switch(nvalue.length)
 {
  case 1:if(kindex > 51)
   obj.value = ovalue;   
   break;
  case 2:if(parseInt(nvalue,10)>36)
   obj.value = ovalue;
   else
   obj.value = nvalue + ":";
   break;
  case 3:check3value(obj,ovalue,nvalue);
   break;
  case 4:check4value(obj,ovalue,nvalue);
   break;
  case 5:check5value(obj,ovalue,nvalue);
   break;
  default:break;
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 obj.focus();
 //window.event.keyCode = 0;
}
function check5value(obj,ovalue,nvalue)
{
 var i = nvalue.indexOf(":");
 nvalue = nvalue.replace(":","");
 switch(i)
 {
  case 2:if(parseInt(nvalue,10) >3600)
   obj.value = ovalue;   
   break;
  default:obj.value = ovalue;
  break;
 }
}
function check4value(obj,ovalue,nvalue)
{
 var i = nvalue.indexOf(":");
 switch(i)
 {  
  case 1:if(parseInt(nvalue.substring(2),10) >59)
   obj.value = ovalue;
   break;
  case 2:nvalue = nvalue.replace(":","");
   if(parseInt(nvalue,10) >360)
   obj.value = ovalue;
   break;
  default:obj.value = ovalue;
  break;
 }
}

function check3value(obj,ovalue,nvalue)
{
 var i = nvalue.indexOf(":");
 switch(i)
 {  
  case 1:break;
  case 2:if(parseInt(nvalue,10) >36)
   obj.value = ovalue;
   break;
  default:obj.value = ovalue;
  break;
 }
}</script>