JavaScript验证函数全解析与实例

//验证是否为空   
function check_blank(obj, obj_name){   
      if(obj.value != ''){      
            return true;      
     }else{      
         alert(obj_name + "所填不能为空！");    
         obj.value = "";   
         return false;      
     }      
}   
  
//过滤输入字符的长度   
function check_str_len(name,obj,maxLength){      
    obj.value=obj.value.replace(/(^\s*)|(\s*$)/g, "");   
    var newvalue = obj.value.replace(/[^\x00-\xff]/g, "**");    
    var length11 = newvalue.length;    
    if(length11>maxLength){   
        alert(name+"的长度不能超过"+maxLength+"个字符！");   
        obj.value="";   
        obj.focus();        
    }    
}   
  
//验证只能为数字   
function checkNumber(obj){   
    var reg = /^[0-9]+$/;   
    if(obj.value!=""&&!reg.test(obj.value)){   
        alert('只能输入数字！');   
        obj.value = "";   
        obj.focus();   

        return false;   
    }   
}   
  
//验证数字大小的范围   
  
function check_num_value(obj_name,obj,minvalue,maxvalue){   
    var reg = /^[0-9]+$/;   
    if(obj.value!=""&&!reg.test(obj.value)){   
        alert(obj_name+'只能输入数字！');   
        obj.value = "";   
        obj.focus();   
        return false;   
    }else if(minvalue>obj.value||obj.value>maxvalue){   
        alert(obj_name+"的范围是"+minvalue+"-"+maxvalue+"!");   
        obj.value="";   
        obj.focus();   
        return false;   
    }   
  
}   
  
//验证只能是字母和数字   
function checkZmOrNum(zmnum){   
  var zmnumReg=/^[0-9a-zA-Z]*$/;   
  if(zmnum.value!=""&&!zmnumReg.test(zmnum.value)){   
     alert("只能输入是字母或者数字,请重新输入");   
     zmnum.value="";   
     zmnum.focus();   
     return false;