help with string concatenate

I am trying to concatenate a string

this is what I have for the string and it compiles

             String tempStr;
                char iptest = Ethernet.localIP();
                tempStr = "GET /es=led_on&ed=18&pld1=";
                tempStr = tempStr + iptest;
                tempStr = tempStr + " HTTP/1.1";

but when I ad this line to use the string

client.println(F(tempStr);

I get this when I try to compile

Arduino: 1.6.7 (Windows 7), Board: "Arduino Pro or Pro Mini, ATmega328 (5V, 16 MHz)"

WARNING: Category '' in library UIPEthernet is not valid. Setting to 'Uncategorized'
In file included from C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Arduino.h:28:0,

                 from sketch\arduino_with_ethernet_shield.ino.cpp:1:

C:\Users\Reg\Desktop\Arduino\arduino_with_ethernet_shield\arduino_with_ethernet_shield\arduino_with_ethernet_shield.ino: In function 'void loop()':

C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/WString.h:38:74: error: initializer fails to determine size of '__c'

 #define F(string_literal) (reinterpret_cast<const __FlashStringHelper *>(PSTR(string_literal)))

                                                                          ^

C:\Users\Reg\Desktop\Arduino\arduino_with_ethernet_shield\arduino_with_ethernet_shield\arduino_with_ethernet_shield.ino:127:32: note: in expansion of macro 'F'

                 client.println(F(tempStr);

                                ^

C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/WString.h:38:74: error: array must be initialized with a brace-enclosed initializer

 #define F(string_literal) (reinterpret_cast<const __FlashStringHelper *>(PSTR(string_literal)))

                                                                          ^

C:\Users\Reg\Desktop\Arduino\arduino_with_ethernet_shield\arduino_with_ethernet_shield\arduino_with_ethernet_shield.ino:127:32: note: in expansion of macro 'F'

                 client.println(F(tempStr);

                                ^

arduino_with_ethernet_shield:127: error: expected ')' before ';' token

/                 client.println(F(tempStr);

                                          ^

exit status 1
expected ')' before ';' token

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Thanks,
yonu

client.println(F(tempStr)); //<<< also note that you are missing one of the closing ")" in your example

The F() macro pulls a string from flash memory where the program itself resides so you can’t alter it
remove the F( ) around the tempStr and see if it works

client.println(tempStr);

also note that you are missing the closing “)” in your example

thanks that did it I didn't even catch the missing )

Thanks,
yonu