JS replaces the carriage return example in the text field
<html><head><title> Headless document </title><script type="text/javascript">function aa(){s=form1.t1.value;s=s.replace(//n|/r/g,"");// add g Global substitution, just replace the first one Is a carriage return, is a newline characterform1.t1.value=s;}</script></head><body><form name="form1"><textarea name="t1" style="height: 74px"></textarea><input type="button" value="aa" onclick="aa()"></form></body></html>