<script>
str=" ";
str1=" \n ";
alert(str.search(/^[ ]+$/)==0);
alert(str1.search(/^[ ]+$/)==0);
</script>
str=" ";
str1=" \n ";
alert(str.search(/^[ ]+$/)==0);
alert(str1.search(/^[ ]+$/)==0);
</script>
/^[ \t]+$/