Return the minimum width of a <p> element:
alert(document.getElementById("myP").style.minWidth);
<!DOCTYPE html> <html> <body> <p style="background:red;min-width:600px;" id="myP"> The minimum width of this paragraph is set to 600px.</p> <button type="button" onclick="myFunction()">Return min width</button> <p id="demo"></p> <script> function myFunction() {/*from w w w. j ava 2s.c om*/ document.getElementById("demo").innerHTML = document.getElementById("myP").style.minWidth; } </script> </body> </html>