php - Echoing success after uploaded -

i want echo "success" on same page form on if uploaded correctly, im new php dont know how done?

index.php

<form action="upload" method="post"> <input name="field1" placeholder="first name" type="text" /> <input type="submit" name="submit" value="submit"> 

upload.php

    $content = "".$_post["field1"]; $fp = fopen("upload/test.txt","wb"); fwrite($fp,$content); fclose($fp); 

i need redirect same page index.php

if need echo on same page , don't want use ajax there 2 possible solution.

a) use parameter on upload script, , thread on index.php (as @brad said @ comment)

upload.php

$content = "".$_post["field1"]; $fp = fopen("upload/test.txt","wb"); fwrite($fp,$content); fclose($fp); header('location: /index.php?m=success'); 

index.php

//check message parameter if (isset($_get['m']{0}) && $_get['m'] === 'success')     echo 'form uploaded successfully';  //display upload form echo '<form action="upload" method="post">' .      '<input name="field1" placeholder="first name" type="text" />' .      '<input type="submit" name="submit" value="submit">'; 

b) within same script index.php

//check if form submitted if (isset($_post['field1'])) {     $content = "".$_post["field1"];     $fp = fopen("upload/test.txt","wb");     fwrite($fp,$content);     fclose($fp);      //do else }  //display form. use index.php action, instead of upload echo '<form action="/index.php" method="post">' .      '<input name="field1" placeholder="first name" type="text" />' .      '<input type="submit" name="submit" value="submit">'; 

update after comment:

when open file fopen function, define 2 arguments. first argument filename, , second argument flags.

you need 'a' (append) flag, instead of 'w' (write):

• 'a' open writing only; place file pointer @ end of file. if file not exist, attempt create it.
• 'w' open writing only; place file pointer @ beginning of file , truncate file 0 length. if file not exist, attempt create it.

take here