function ValidateTime(strval)
{
  //var strval = document.Form1.TextBox1.value;
  var strval1;

  //minimum lenght is 6. example 1:2 AM
  if(strval.length < 6)
  {
   //alert("Invalid time.  Time format should be HH:MM AM/PM.");
   return false;
  }

  //Maximum length is 8. example 10:45 AM
  if(strval.lenght > 8)
  {
   //alert("Invalid time.  Time format should be HH:MM AM/PM.");
   return false;
  }

  //Removing all space
  strval = trimAllSpace(strval);

  //Checking AM/PM
  if(strval.charAt(strval.length - 1) != "M" && strval.charAt(
      strval.length - 1) != "m")
  {
   //alert("Invalid time.  Time shoule be end with AM or PM.");
   return false;
  }
  else if(strval.charAt(strval.length - 2) != 'A' && strval.charAt(
      strval.length - 2) != 'a' && strval.charAt(
      strval.length - 2) != 'p' && strval.charAt(strval.length - 2) != 'P')
  {
   //alert("Invalid time.  Time should end with AM or PM.");
   return false;
  }

  //Give one space before AM/PM

  strval1 = strval.substring(0,strval.length - 2);
  strval1 = strval1 + ' ' + strval.substring(strval.length - 2,strval.length);
  var AMPM = strval.substring(strval.length - 2,strval.length).toUpperCase();

  strval = strval1;

  var pos1 = strval.indexOf(':');
  //document.Form1.TextBox1.value = strval;

  if(pos1 < 0 )
  {
   //alert("Invlalid time.  A colon(:) is missing between hour and minute.");
   return false;
  }
  else if(pos1 > 2 || pos1 < 1)
  {
   //alert("Invalid time.  Time format should be HH:MM AM/PM.");
   return false;
  }

  //Checking hours
  var horval =  trimString(strval.substring(0,pos1));

  if(horval == -100)
  {
   //alert("Invalid time.  Hour should contain only integer value (0-11).");
   return false;
  }

  if(horval > 12 && AMPM == 'AM')
  {
   //alert("Invalid time.  Hour can not be greater that 12.");
   return false;
  }
  else if(horval > 23 && AMPM == 'PM')
  {
    return false;
  }
  else if(horval < 0)
  {
   //alert("Invalid time.  Hour can not be hours less than 0.");
   return false;
  }
  //Completes checking hours.

  //Checking minutes.
  var minval = trimString(strval.substring(pos1+1,pos1 + 3));

  if(minval == -100)
  {
   //alert("Invalid time.  Minute should have only integer value (0-59).");
   return false;
  }
 
  if(minval > 59)
  {
     //alert("Invalid time.  Minute can not be more than 59.");
     return false;
  }
  else if(minval < 0)
  {
   //alert("Invalid time.  Minute can not be less than 0.");
   return false;
  }

  //Checking minutes completed.

  //Checking one space after the mintues
  minpos = pos1 + minval.length + 1;
  if(strval.charAt(minpos) != ' ')
  {
   //alert("Invalid time.  Space missing after minute.  Time should have HH:MM AM/PM format.");
   return false;
  }
  return true;
}

function trimAllSpace(str)
{
    var str1 = '';
    var i = 0;
    while(i != str.length)
    {
        if(str.charAt(i) != ' ')
            str1 = str1 + str.charAt(i); i ++;
    }
    return str1;
}

function trimString(str)
{
     var str1 = '';
     var i = 0;
     while ( i != str.length)
     {
         if(str.charAt(i) != ' ') str1 = str1 + str.charAt(i); i++;
     }
     var retval = IsNumeric(str1);
     if(retval == false)
         return -100;
     else
         return str1;
}

function IsNumeric(strString)
{
    var strValidChars = "0123456789";
    var strChar;
    var blnResult = true;
    //var strSequence = document.frmQuestionDetail.txtSequence.value;
    //test strString consists of valid characters listed above
    if (strString.length == 0)
        return false;
    for (i = 0; i < strString.length && blnResult == true; i++)
    {
        strChar = strString.charAt(i);
        if (strValidChars.indexOf(strChar) == -1)
        {
            blnResult = false;
        }
    }
    return blnResult;
}