i used the following htaccess rule and it successfully worked.
RewriteRule ^([0-9a-zA-Z-\s]*)$ main_page.php?page=$1 [L]**
but when i used the above rule for sub page it didnt work and redirected to main_page.php
RewriteRule ^([0-9a-zA-Z-\s]*)$ sub_page.php?spage=$1 [L]**
