My virgin mobile phone won't let me go onto the internet. How do I fix this?

When I try to search a site or to check my yahoo mail on my virgin mobile phone it says "cannot connect to server" or something like that. What is the problem? Can someone help?My virgin mobile phone won't let me go onto the internet. How do I fix this?i had this problem too but it only happened when i had $3.00 or less on my phone account balance. after i got more money on my balance it allowed me to. you also have to be in good service areas