Setence Case using Javascript/SQL Server

How to  Change aaa or AAA to be Aaa

<script type="text/javascript" language="javascript"> 
    function CorrectName(e){     
        if(e.value != "" && /^[a-zA-Z]/.test(e.value)){     
           e.value=e.value.substring(0,1).toUpperCase()+e.value.substring(1).toLowerCase();     
        }     
        }     
    </script><asp:TextBox onkeyup="CorrectName(this)" onblur="CorrectName(this);" ID="txtFirstName"    
        runat="server" Width="130px" MaxLength="20"></asp:TextBox> 
UPDATE TableName SET first_name=upper(first_name)    
WHERE len(first_name)=1; UPDATE TableName SET first_name=upper(left(first_name,1))+ lower(substring(first_name,2, len(first_name)-1))    
WHERE len(first_name)>1;