实用的注册表单验证代码

  1 <script language="javascript">      
  2 function IsDigit(cCheck)      
  3  {      
  4  return (('0'<=cCheck) && (cCheck<='9'));      
  5  }      
  6       
  7 function IsAlpha(cCheck)      
  8  {      
  9  return ((('a'<=cCheck) && (cCheck<='z')) || (('A'<=cCheck) && (cCheck<='Z')))      
 10  }               
 11        
 12 function IsaNull(cCheck)           
 13  {           
 14  return(cCheck != " ")          
 15  }                                
 16        
 17 function checkform()      
 18 {  
 19   id = document.sform1.id.value;      
 20  if (id == "")      
 21   {      
 22   alert("请输入注册名");      
 23   document.sform1.id.focus();      
 24   return false;      
 25   }      
 26       
 27  for (nIndex=0; nIndex<id.length; nIndex++)      
 28   {      
 29   cCheck = id.charAt(nIndex);      
 30   if (!(IsDigit(cCheck) || IsAlpha(cCheck) || cCheck=='-' || cCheck=='_' || cCheck=='.'))      
 31    {      
 32    alert("用户名只能使用字母、数字以及-、_和.，并且不能使用中文");      
 33    document.sform1.id.focus();      
 34    return false;      
 35    }      
 36   }  
 37   chineseid = document.sform1.chineseid.value;      
 38  if (chineseid == "")      
 39   {      
 40   alert("请输入中文昵称");      
 41   document.sform1.chineseid.focus();      
 42   return false;      
 43   }     
 44  password = document.sform1.password.value;      
 45  if (password == "")      
 46   {      
 47   alert("请输入登陆密码");      
 48   document.sform1.password.focus();      
 49   return false;      
 50   }  
 51  password1 = document.sform1.password1.value;      
 52  if (password>password1)      
 53   { 
 54      alert("重复密码与登陆密码不相同");      
 55   document.sform1.password.focus();  
 56                                 document.sform1.password1.focus();      
 57   return false; 
 58   }   
 59 if (password<password1)      
 60   { 
 61      alert("重复密码与登陆密码不相同");      
 62   document.sform1.password.focus();  
 63                                 document.sform1.password1.focus();      
 64   return false; 
 65   }  
 66  if (document.sform1.email.value == "")      
 67   {      
 68   alert("请输入您的E-MAIL地址");      
 69   document.sform1.email.focus();      
 70   return false;      
 71   }      
 72        
 73  email=document.sform1.email.value;       
 74  emailerr=0      
 75  for (i=0; i<email.length; i++)      
 76   {      
 77   if ((email.charAt(i) == "@") & (email.length > 5))      
 78    {      
 79      emailerr=emailerr+1      
 80    }      
 81   }      
 82  if (emailerr != 1)      
 83   {      
 84   alert("请输入正确的E-MAIL地址");      
 85   document.sform1.email.focus();      
 86   return false;      
 87   }            
 88    
 89  if (document.sform1.checkask.value=="")  
 90   {  
 91    alert("密码提示问题不能为空");      
 92    document.sform1.checkask.focus();      
 93    return false;   
 94   }  
 95  if (document.sform1.checkans.value=="")  
 96   {  
 97    alert("您的密码提示问题答案不能为空");  
 98    document.sform1.checkans.focus();      
 99    return false;   
100   }
101  return true;      
102       
103 }  
104 </script>