如何删除字符串中的所有断行?

I have a text in a textarea and I read it out using the .value attribute. Now I would like to remove all linebreaks(the character that is produced when you press enter) from my text now using .replace with a regular expression, but how do I indicate a linebreak in a regex? If that is not possible, is there any other way?I have a text in a textarea and I read it out u