If condition Then
    [statements1]
Else
    [statements2]
End If

上边是VBScript脚本If语句的语法，当condition值为True时执行statements1，当condition值为False时执行statements2，由于VBScript的类型自动转换功能，当condition的值为非0的数值时和True等效，当condition的值为0时和False等效。

实际运用中，我们必须对condition的值有充分的认识，才能对If语句的流程胸有成足。下边我们再举一些例子来加深记忆：

<%
Dim condition
condition = Response.IsClientConnected
If condition Then
    Response.write("True")
Else
    Response.write("False")
End If
'condition = True  ,  Result:True
'condition = False ,  Result:False
'condition = 2     ,  Result:True
'condition = 0.01  ,  Result:True
'condition = 0     ,  Result:False
'condition = 0.00  ,  Result:False
'condition = isNumeric(3)    , Result:True
'condition = isNumeric("aa") , Result:False
'condition = Array(0,1,"aa","bb")(0) , Result:False
'condition = Array(0,1,"aa","bb")(1) , Result:True
'condition = Response.IsClientConnected , Result:True
%>