1.判断内容为空的函数
function CheckEmpty(Field, FieldTitle)
{
?if (Field.value == "")
?{
? alert("请在\"" + FieldTitle + "\"一栏中输入内容.");
? Field.focus();
? return false;
?}
?
?return true;
}
?

2.判断内容是否为数字,并且为整数的函数
function CheckInteger(Field, FieldTitle)
{
?if (Field.value != "")
?{
? for (i = 0; i < Field.value.length; i++)
? {
?? ch = Field.value.charAt(i);
???
?? if ( (ch < '0' || ch > '9') && ch != '-' ) {
??? alert("\"" + FieldTitle + "\"中只能输入数字.");
??? Field.focus();
??? return false;
?? }
? }
?}
?
?return true;
}
?

3.判断内容是否为数字,并且为小数的函数
function CheckReal(Field, FieldTitle)
{
?if (Field.value != "")
?{
? DotNum = 0;
? for (i = 0; i < Field.value.length;? i++)
? {
?? ch = Field.value.charAt(i);
???
?? if ((ch < '0' || ch > '9') && ch != '.')
?? {
??? alert("\"" + FieldTitle + "\"中只能输入数字.");
??? Field.focus();
??? return false;
?? }
???
?? if (ch == '.')
?? {
??? if (DotNum > 0)
??? {
???? alert("\"" + FieldTitle + "\"中只能输入一个小数点.");
???? Field.focus();
???? DotNum++;
???? return false;
??? }
?? }
? }
?}
?
?return true;
}

4.判断内容长度是否超过指定长度的函数

function CheckMaxLength(Field, MaxLength, FieldTitle)?
{?
?if (Field.value != "")?
?{?
? if (Field.value.length > MaxLength)?
? {?
?? alert("\"" + FieldTitle + "\"中输入的字符请不要超过" + MaxLength + "字符.");?
?? Field.focus();?
?? return false;?
? }?
?}?
????
?return true;?
}

5.判断内容长度是否小于指定长度的函数
function CheckMinLength(Field, MinLength, FieldTitle)?
{?
?if (Field.value != "")?
?{?
? if (Field.value.length < MinLength)?
? {?
?? alert("\"" + FieldTitle + "\"中输入的字符请不要少于" + MinLength + "字符.");?
?? Field.focus();?
?? return false;?
? }?
?}?
????
?return true;?
}?

?6.判断复选框中的值是否选中的函数
function CheckOption(Field, FieldTitle)
{
?for (i = 0; i < Field.length; i++)
? if (Field[i].checked)
?? return true;
???
?alert("请选择\"" + FieldTitle + "\"中的值.");
?return false;
}
?
function Checkselect(Field, FieldTitle)
{
?if (Field.options[Field.selectedIndex].value=="")
?{
? alert("请选择\"" + FieldTitle+"\"" );
? Field.focus();
? return false;
?}
?return true;
}

7.此函数用于判断邮箱Email地址是否正确
function CheckEmail(Field)
{
?? // there must be >= 1 character before @, so we
?? // start looking at character position 1
?? // (i.e. second character)
?? var i = 1;
?? var len = Field.value.length;
?if (len > 50)
?{
? window.alert("email地址长度不能超过50位!");
? return false;
?}
?pos1 = Field.value.indexOf("@");
?pos2 = Field.value.indexOf(".");
?pos3 = Field.value.lastIndexOf("@");
?pos4 = Field.value.lastIndexOf(".");
?//check '@' and '.' is not first or last character
?if ((pos1 <= 0)||(pos1 == len-1)||(pos2 <= 0)||(pos2 == len-1))?
?{
? window.alert("请输入有效的E-mail地址！");
? Field.focus();
? return false;
?}
?else
?{
? //check @. or .@
? if( (pos1 == pos2 - 1) || (pos1 == pos2 + 1)
??? || ( pos1 != pos3 )? //find two @
??? || ( pos4 < pos3 ) ) //. should behind the '@'???
? {
?? window.alert("请输入有效的E-mail地址！");
?? return false;
? }
?}
?return true;
}

8.判断输入框中的值是否为指定的长度(可以判断手机号,身份证号等)
function CheckMustLength(Field, MustLength, FieldTitle)?
{?
? if (Field.value.length != MustLength)?
? {?
?? alert("\"" + FieldTitle + "\"中输入的值必须是" + MustLength + "位.");?
?? Field.focus();?
?? return false;?
? }?
?return true;?
}?
??
function CheckIntRange(field,prompt,min,max) {?
?if ( ! CheckInteger(field,prompt) )?
? return false;?
?ival = parseInt(field.value);?
?if ( ival < min || iv