function isEmpty(word,alertword) {
    if (word.value.length==0) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }
  
  function isLengthBig(word,wordlength,alertword) {
    if (word.value.length<wordlength) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isLengthSmall(word,wordlength,alertword) {
    if (word.value.length>wordlength) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isBig(word,wordlength,alertword) {
    if (word.value<wordlength) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isSmall(word,wordlength,alertword) {
    if (word.value>wordlength) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isEqual(word1,word2,alertword) {
    if (word1.value!=word2.value) {
      alert(alertword);
      word1.focus();
      return true;
    } else {
      return false;
    }
  }

  function isNotEqual(word1,word2,alertword) {
    if (word1.value==word2.value) {
      alert(alertword);
      word1.focus();
      return true;
    } else {
      return false;
    }
  }
  
  function isEmail(word,alertword) {
    if (word.value.indexOf(".")<0 || word.value.indexOf("@")<0) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isLength(word,wordlength,alertword) {
    if (word.value.length!=wordlength) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isNumber(word,alertword) {
    if (isNaN(word.value)) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isWrongChar(word,alertword) {
    for (var i=0;i<(word.value.length);i++) {
     if (word.value.charAt(i)<'0'||word.value.charAt(i)>'9') { 
       if (word.value.charAt(i)<'a'||word.value.charAt(i)>'z') {
         if (word.value.charAt(i)<'A'||word.value.charAt(i)>'Z') {
           if (word.value.charAt(i)!='_') {
             alert(alertword);
             return true;            
           } 
         }
       }
     }
    }
    return false;
  }

  function isSelected(word,alertword) {
    if (word.selectedIndex==0) {
      alert(alertword);
      word.focus();
      return true;
    } else {
      return false;
    }
  }

  function isRadio(word,alertword) {
    var i;
    var cRadio=false;
    if (word.length) {
      for (i=0;i<word.length;i++) {
        cRadio=cRadio || word[i].checked;
      }
    } else {
      cRadio = cRadio || word.checked;
    }
    if (!cRadio) {
      alert(alertword);
      return true;
    } else {
      return false;
    }
  }
  
  function getWeek() {
    today=new Date();
    var day;var date;
    var time_start=new Date();
    var clock_start=time_start.getTime()
    if(today.getDay()==0)day="    星期日"
    if(today.getDay()==1)day="    星期一"
    if(today.getDay()==2)day="    星期二"
    if(today.getDay()==3)day="    星期三"
    if(today.getDay()==4)day="    星期四"
    if(today.getDay()==5)day="    星期五"
    if(today.getDay()==6)day="    星期六"
    date=(today.getYear())+"年"+(today.getMonth()+1)+"月"+today.getDate()+"日 ";
    document.write(date);document.write(day+"</font></span>");
  }