function LeftStr(S:string;Count:integer):string; 
begin  //获取字符串左边起n个字符   
        LeftStr:=Copy(s,1,Count); 
end;  

function RightStr(S:string;Count:integer):string; 
begin  //获取字符串右边起n个字符   
        RightStr:=Copy(s,Length(s)-Count+1,Count); 
end;  

function ReplaceStr(S:string;OldStr,NewStr:string):string; 
var i,j:integer;     ss:string; 
begin  //替换字符串 (其实Delphi已经提供对应的函数了StringReplace）   
        i:=1;   
        ss:='';   
        j:=length(OldStr);   
        while i<=length(s)         do  
        begin  
                if LowerCase(copy(s,i,j))=LowerCase(OldStr)  then  
                begin  
                        ss:=ss+NewStr;  
                        inc(i,j);  
                end  
                else  
                begin  
                        ss:=ss+s[i];  
                        inc(i,1);  
                end;  
        end;  
        Result:=ss; 
end;  

function LTrim(S:string):string; 
begin //删除字符串左边空格  
        s:=s+'*';  
        s:=Trim(s);  
        Delete(s,length(s),1); 
end;  

function RTrim(S:string):string; 
begin //删除字符串右边空格  
        s:='*'+s;  
        s:=Trim(s);  
        Delete(s,1,1); 
end;  

function LDelete(S,Sub:string):string; 
begin //删除字符串左边的某一所有字符  
        while LeftStr(S,1)=sub do  
                Delete(S,1,1);  
        LDelete:=s; 
end;  
        
function RDelete(S,Sub:string):string; 
begin //删除字符串右边的某一所有字符  
        sub:=copy(sub,1,1);  
        while RightStr(S,1)=sub do  
                Delete(S,length(s),1);  
        RDelete:=s; 
end;  

function MDelete(S,Sub:string):string; 
begin //删除字符串中包含的某一所有字符  
        sub:=copy(sub,1,1);  
        while Pos(sub,s)>0 do     
                Delete(S,Pos(sub,s),1);   
        MDelete:=s; 
end;  

function GetCodeNo(NoStr:string;NoLen:integer):string; 
begin  //生成一个在数字前面自动补零编码   
        NoStr:=Trim(NoStr);   
        Result:=copy('00000000000000000000',1,NoLen-length(NoStr))+NoStr; 
end;