php - json_decode returning blank -

i working on facebook app. have stored values in database in json format.

when fetching value on target page , trying display value follow :

$sql = mysql_query("select * `beforepublish` `tabid` = '$page_id'") or die(mysql_error()); $sql = mysql_fetch_assoc($sql);  $contest_id = $sql['contestid']; $temp_id = $sql["tempid"]; $value = $sql["values"]; $returnvalue = json_decode($value); echo "<pre>"; print_r($returnvalue); echo "</pre>"; 

here value of

$value = {"image":"upload_1182341221.jpg","conttxt":"get chance win samsung galaxy tab "}

and getting $returnvalue blank.

but when try :

$returnvalue = json_decode('{"image":"upload_1182341221.jpg","conttxt":"get chance win samsung galaxy tab "}'); echo "<pre>"; print_r($returnvalue); echo "</pre>"; 

then $returnvalue returning :

stdclass object (     [image] => upload_1182341221.jpg     [conttxt] => chance win samsung galaxy tab  ) 

so guys, please me, why getting blank value in previous case ?

edit

vardump($value) returning :

string '{"image":"upload_1182341221.jpg","conttxt":"get chance win samsung galaxy tab     "}' (length=86) 

string '{"image":"upload_1182341221.jpg","conttxt":"get chance win samsung galaxy tab     "}' (length=86) 

there problem. linebreak , tab. should like:

string '{"image":"upload_1182341221.jpg","conttxt":"get chance win samsung galaxy tab"}' (length=84) 

this why var_dump() outputs length, can validate against unwanted/invisible characters.

---

you can store line breaks in javascript strings \n.
json_encode() automatically.

this applies escape sequences (commonly used ones \n, \r, \t , \b).