如何让“输入”键在文本区域提交表单

I have a chat that uses textarea instead of text for obvious reasons. This is why each time members hit ENTER they get a new line instead of sending the message. I would like to change this, so every time they hit ENTER =the message to be submitted and then the cursor to return on textarea for their next message typing. I've tried different codes found on this site, most didnt work and those who seemed to do something were just refreshing the page and i got a blank page.I have a chat that uses textarea instead of tex