i am a layman. don't know anything much about magento based website. i can not open my website and it is not letting me login to admin page. it says
/home/himalaya/public_html/app/code/core/Mage/Captcha/Block/Captcha.php on line 43
Also try searching the code string/error when you see it:
app/code/core/Mage/Captcha/Block/Captcha.php on line 43
If it's a common error, others may have posted the same question or answer elsewhere and you can narrow down your search with this info.