Search button seems wrong

Hi,
I have added CSS to my search widjet:

.widget .search-field {
width: 70%;
}

.widget_search .search-submit {
display: inline-block;
}

And the search button appeared as i wanted. But it has some strange simbols on it instead of word Search or something like that. How can i add a word on it?

And the next question with search widjet is how i can remove Search text in search area?

Thank you.