Here is the complete Validations for checking all numbers with plus minus.

1) first Create a JavaScript File name as (all-numbers-with-plus-minus.js) . Put Below Code inside that file  . Note for separete Js file dont use Script Start Syntax.
[code type=javascript][/code]

2) In Second Stage Create a Html File Named as (example-javascript-form-validation-checking-all-numbers-with-plus-minus.html). Put below code as Given Here.
[code type=html]

JavaScript form validation – An integer with an optional leading plus(+) or minus(-) sign

[/code]

3) For applying designing to the page use below Css Code. Name to that File is (form-style.css).
[code type=css]li {list-style-type: none;
font-size: 16pt;
}
.mail {
margin: auto;
padding-top: 10px;
padding-bottom: 10px;
width: 400px;
background : #D8F1F8;
border: 1px soild silver;
}
.mail h2 {
margin-left: 38px;
}
input {
font-size: 20pt;
}
input:focus, textarea:focus{
background-color: lightyellow;
}
input submit {
font-size: 12pt;
}
.rq {
color: #FF0000;
font-size: 10pt;
}[/code]

One you run the Above code you can apply the Validation to the Webpage. you can also downland complete Code here. checking-all-numbers-with plus-minus