<textarea name="TextBox1" rows="6" cols="35" id="TextBox1"></textarea>
<input type="button" value="Read" onClick="testGG()">
<script language="javascript">
function testGG(){
var xxx = document.getElementById("TextBox1");
var yyy = xxx.value.split("\n");
for(var i = 0;i < yyy.length;i++){
alert(yyy[i]);}
}
</script>
<input type="button" value="Read" onClick="testGG()">
<script language="javascript">
function testGG(){
var xxx = document.getElementById("TextBox1");
var yyy = xxx.value.split("\n");
for(var i = 0;i < yyy.length;i++){
alert(yyy[i]);}
}
</script>
var content = textbox1.value.split('\n').join('<br>');
newCon.value = content;
<input type=hidden id=newCon runat=server>
.cs
string content = newCon.Value;