jQuery validation for price field.

Please follow example for set jquery validation for price field.

HTML
<input id="price" maxlength="7" type="text" />

Javascript
$("#price").on("keyup", function(){
    var valid = /^\d{0,4}(\.\d{0,2})?$/.test(this.value),
        val = this.value;
   
    if(!valid){
        console.log("Invalid input!");
        this.value = val.substring(0, val.length - 1);
    }
});

Enjoy!